JP3286329B2 - Image data transmission method, image reproducing apparatus, and image reproducing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of transmitting image data suitable for reproducing an animation used for, for example, a game, a recording medium on which the image data is recorded,
Furthermore, the present invention relates to an image data reproducing device.

[0002]

2. Description of the Related Art A CD-ROM has a large recording capacity and is used as an external storage medium in game machines and personal computers using microcomputers. Moving image data is recorded on the CD-ROM. It has been considered that the image data is read out and supplied to a host computer to display a moving image (animation) on a CRT display.

In this case, a conventional game machine uses a CD.
-The method of reading image data from ROM is CD
Rather than continuously reading image data from the ROM and displaying a moving image on a display, an image of a moving image composed of a plurality of frames recorded in a predetermined recording area of the CD-ROM by appropriately seeking the CD-ROM. The data is read and transferred to a large-capacity RAM provided in the host computer, and an animation is created from a plurality of frames of image data stored in the RAM and displayed.

[0004]

However, the conventional animation method described above has a drawback that the number of frames per second of a moving image is small and a smooth animation cannot be obtained.

In view of the above, the applicant of the present invention has disclosed in Japanese Patent Application No. 3-74555, reproducing a moving image while continuously reading image data from a CD-ROM. A method that can realize animation is proposed.

[0006] By the way, it is important for a game machine to have interactivity (interactivity). For example, the enemy aircraft 9 displayed on the screen 91 of FIG.
When the user attacks on 2, a different screen must be prepared according to the result. That is,
When a bullet hits an enemy aircraft, an image of the explosion pattern of the enemy aircraft must be displayed as shown in a screen 93 in FIG.
On the other hand, when the attack has failed, an image in which the bullet 95 has missed the enemy aircraft 92 must be displayed on the display as shown in a screen 94 in FIG.

[0007] The above-mentioned interactivity is realized by the CD-
In order to realize even an animation from a ROM, the screen 93 and the screen 94 must always be combined. At this time, for example, it is conceivable that one screen, for example, an explosion pattern is recorded in a special recording area separately, and the recording area is appropriately sought according to the correspondence of the user to project the screen of the explosion pattern. However, this method takes a long time for seeking and impairs entertainment.

Therefore, it is conceivable to compress the image data with higher efficiency and always record the image data of the screen 93 and the screen 94 as one screen. However, in this case, there is a problem that the image quality is deteriorated because the compression ratio is large.

An object of the present invention is to provide a method of transmitting image data , an image reproducing apparatus, and the like, which enable a plurality of screens to be instantaneously switched according to a user's correspondence, such as a game .
Another object is to provide an image reproducing method .

[0010]

According to the present invention, a foreground is provided.
Image data of a moving image consisting of
This is a transmission method that transmits data in units of frames consisting of sectors.
Was assigned as background for multiple foregrounds
Image data representing one background is divided into multiple frames
Image data representing the divided background,
Represents multiple foregrounds that should be selectively superimposed on the foreground
The image data is transmitted by the plurality of frames.
Image data transmission method characterized by transmitting
You.

In this image data transmission method, the background can be a still image.

According to the present invention, the image data representing the background
Data and a plurality of types that are selectively displayed in the background
The image data representing the scenery is
, Which are sequentially recorded and operated in frame units.
And the background is one screen of the background.
Is divided into a plurality of frames and recorded.
From the recording medium on which the recorded image data is recorded
Image reproducing device having a function of reading out and reproducing image data
The foreground of the plurality of foregrounds according to an instruction.
Means for selecting a foreground to be shown, and an image from the storage medium
Means for reading data; and means for reading the read image data.
First writing means for writing to a buffer memory;
The back divided into a plurality of frames from the buffer memory
The image data corresponding to the scene is read out and the first image memo is read.
Area, and select from the buffer memory.
The image data corresponding to the selected foreground is stored in the second image memo.
A second writing means for writing to the rear area;
Before being divided into multiple frames from the image memory area
Image data representing the background is read for a plurality of frames,
And displaying the background from the second image memory area.
Image data representing the foreground to be displayed overlaid with the image data
Data, read them out, combine them and display them on the display
And display means for causing the first display means to perform the first
Images for multiple frames written in the image memory area
In the background obtained from the image data,
Display by overlapping multiple recorded foregrounds sequentially
The video is projected by displaying it on the
The writing unit is configured to perform the selection during the projection by the display unit.
If another foreground is selected by the means to
At this point, the newly selected foreground from the buffer memory
Writes the corresponding image data to the second image memory area
An image reproducing apparatus is provided.

[0013]

In the above-described method according to the present invention, a moving image is divided into a background and a foreground. And the background image is
Only one frame of image data is transmitted (recorded) in a plurality of frames in a so-called frame-dropped state instead of data of all frames. The amount of data that can be transmitted (recorded) as the foreground increases by the amount of dropped frames in the background. Therefore, a plurality of images can be transmitted (recorded) as the foreground.

In the image reproducing apparatus according to the present invention, the reproduction signal from the recording medium is written to the buffer memory by the first writing means. The background image data from the buffer memory is written to the first image memory area. The image data selected from the plurality of foreground image data in the buffer memory is:
The data is written to a second image memory area different from the first image memory area.

Then, the background image data is read from the first image memory area to reproduce the background image, and the foreground image data is read from the second image memory area. The target screen is displayed by the combination of.

The contents of the second image memory area are selected from a plurality of foreground images by a selection signal. Therefore, for example, in a game machine, if the foreground to be selected is switched according to the correspondence of the user, the screen can be immediately switched to the screen corresponding to the correspondence of the user.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a method for transmitting image data according to the present invention, a recording medium used in the method and an image reproducing apparatus will be described below with reference to the drawings. In this example, the recording medium is a CD-ROM, and the image reproducing device is a game machine.

In the image reproducing apparatus of this example, as will be described later, a moving image is reproduced while continuously reading image data from a CD-ROM to realize an animation with a large number of frames and a smooth movement, and Is divided into a background and a foreground so that an image of the foreground can be instantaneously switched so that an image having an interactive property can be reproduced.

Before explaining the present invention, in order to facilitate understanding of the present invention, one moving image is recorded on a CD-ROM without being divided into a background and a foreground, and reproduced by an image reproducing apparatus. Will be described. First, a data compression method for image data and a compressed moving image data are stored in a CD-RO as a recording medium.
A method for recording in M will be described.

[Data Compression Method for Moving Picture Image Data] FIGS. 9 and 10 are block diagrams of an example of an encoding apparatus that executes the image data compression method of this embodiment. In this example, the compressed image data is recorded on a CD-ROM. This CD-ROM is used as software for a game machine as described later, and image data is highly efficiently compressed so that a moving image can be reproduced.

In this example, one frame (one screen)
As shown in FIG. 11A, is composed of, for example, horizontal × vertical = 256 pixels × 192 pixels, and one pixel is represented by 5 bits for each of three primary colors. Actually, one dummy bit is added to the highest order for the sake of processing, and one pixel is composed of 1 bit (dummy) +5 bits × 3 colors, that is, 1 bit.
It is 6 bits. Then, the original image data is subjected to data compression processing in units of one frame as follows.

That is, the data of one frame of the original image is supplied to the character dividing means 22 through the input terminal 21, and as shown in FIG. 11B, the image of one frame is composed of horizontal × vertical = 8 pixels × 8 pixels. It is divided into small area blocks (this block is hereinafter referred to as a character). Therefore, as shown in FIG. 11B, an image of one frame is divided into 32 × 24 = 768 characters. Then, image data C (0) to C of each character
(767) is temporarily stored in the register 23.

The image data C (0) to C (767) of each character from the register 23 is supplied to the first vector quantization means 24. Also in this example, in the vector quantization means 24, image data C (0) to C (767) of each character are processed in parallel. Of course, the image data C (0) to C (767) may be sequentially vector-quantized without performing the parallel processing. The same applies to each processing described later.

The vector quantization means 24 performs vector quantization for each character image data C (k) (k = 0 to 767) such that the number of colors represented as pixels in the character is within four. Done.

Various methods have been proposed for this vector quantization, but in this example, red,
When considering a three-dimensional color space in which the color components of the three primary colors of blue and green are orthogonal to each other, the distance between each pixel in the color space is obtained, and pixels having short distances from each other are collected, that is, approximated. By performing a process of combining pixels having different colors into one representative color, the pixel data is rounded so that the colors of the pixels in the character fall within four or less representative colors.

Then, for all the characters in one frame, vector quantization is performed so that the colors of the pixels in the character fall within four colors, and then the quantization error (the position of the representative color) in all the characters in the one frame , The maximum value Emax of the representative color and each pixel in the color space is determined. At this time, a threshold value Eth allowed as the maximum value of the quantization error in one frame is set in advance.

Then, the maximum value Emax of the quantization error is compared with a threshold value Eth. When the maximum value Emax of the quantization error is larger than the threshold value Eth, vector quantization is further performed on the image data in each character until immediately before the quantization error exceeds the maximum value Emax. Reduce the number of colors. This is to make the S / N of the image data in all the characters in one frame uniform. This is performed until immediately before the maximum value Emax of the quantization error exceeds the threshold value Eth. In this way, S in all frames
The / N ratio is kept constant.

When the quantization is performed as described above, the number of pixel colors is reduced in a character having a flat color change. This is because, for a character having a flat color change, the quantization error does not increase so much even if the number of colors decreases. In this process, some characters have two colors in the character and only one color. Then, the color selected in each character is set as the representative color.

Thus, from the vector quantization means 24, image data compressed to four colors or less in each character is obtained. The image data in character units from the vector quantization means 24 is supplied to the palette dividing means 25.

The palette dividing means 25 classifies the characters into eight groups (each group is referred to as a palette) by grouping characters having similar colors according to the distribution of colors in the character. For example, as shown in FIG. 11C, if a group of characters having similar colors according to the content of the image occurs as A, B, C, D, E,..., The groups A, B, C,
A pallet is constructed for each of D, E,.

In the case of this example, the method of allocating eight palettes is as follows: (1) It is assumed that the representative color of each character (the average value of the colors in the character) is calculated, and that each character is composed of the representative color. (2) Vector quantization is performed, and all characters in one frame are quantized into eight colors. That is, since the number of characters is 768, the representative color of the character is a maximum of 768.
The colors are quantized into eight-color characters. (3) Characters having the same label (representative color) are combined into one palette. This is performed in three steps.

Note that the group of characters constituting this palette need not be in a continuous character area, and the characters that are skipped may constitute one palette group.

Eight pallet data P (0) to P (7)
Are temporarily stored in a register 26, respectively, supplied to a second vector quantization means 27, and subjected to parallel processing.

The second vector quantization means 27 determines representative colors of 16 pixels for each pallet. At this time, if the number of colors of the pixels in one palette is larger than 16 colors, vector quantization is performed and the colors in the palette are rounded to 16 colors in the same manner as in the character. Then, the resulting 16 colors are set as the representative colors of the pixels.

Thus, each of the eight colors rounded to 16 colors
Image data P (0) to P for each pallet in character units
(7) are supplied to the labeling means 28 and are processed in parallel. In each of the labeling means 28, color conversion tables COL (0) to COL (0) to 16 colors or less than 16 color data selected as representative colors of pixels for each palette
OL (7) is created and temporarily stored in the register 29 (see FIG. 12). The data of the color conversion tables COL (0) to COL (7) from the register 29 is supplied to the recording processing means 38 as recording data.

Each of the labeling means 28 refers to each of the color conversion tables COL (0) to COL (7), and calculates 16 characters for each character included in each palette.
The pixel data rounded to a color is converted into label image data LAB (0) to LAB (7) in which the color of the pixel is represented by a corresponding color number on the color conversion table of the palette (each character). 13 is shown in FIG. 13). Then, the label image data LAB (0) to LAB (7) are temporarily stored in the register 30.

In this case, as described above, in the label image data LAB (0) to LAB (7), the character is composed of four or three colors (FIG. 13A) and composed of two colors (FIG. 13B). , Consisting of only one color (FIG. 13)
C). When the character is four or three colors, if there is a table indicating the color numbers of the four or three colors, each pixel data indicates which one of the color number tables.
It can be represented by bit data. Therefore, each pixel data of a character composed of four or three colors can be represented by two bits. Similarly, if the character has two colors, it can be represented by a color number table of two colors of the character and 1-bit pixel data. Further, if there is only one color, only the color data can be used as described later.

A character that can be represented by 2 bits is referred to as a 2-bit mode character, a character that can be represented by 1 bit is referred to as a 1-bit mode character, and a character having only one color is referred to as a single color character.

In consideration of the decoding process, high-speed processing can be achieved by treating the 2-bit mode character, the 1-bit mode character, and the single-color character collectively. However, in the 768 characters in one frame, generally, each mode character is dispersedly mixed as shown in FIG. 14A. In FIG. 14,
A bit mode character is a 2-bit mode character, and a circle is a single color character.

Therefore, the label image data LAB (0) to LAB (7) of each pallet from the register 30 are supplied to the sorting means 31, and as shown in FIG. One frame of character data is rearranged in the order of monochromatic characters.

In the sorting means 31, a table (hereinafter referred to as a screen table) s for rearranging the characters of one frame in the original order is provided.
cr is formed. This screen table scr is
As shown in FIG. 15, when an image of one frame is divided into small areas having the same size as a character, a character number CNo. And a pallet number PNo.

The character number CNo. Is the character order in one frame after sorting the characters to be displayed at the position of the small area. Also, pallet number PN
o indicates which of the eight palettes contains the character displayed in the small area. That is, it indicates which color conversion table is used at the time of decoding. In this case, the character number CNo. And the pallet number PNo. Of one small area are composed of, for example, 2-byte data.

In the case of this example, the character number CN
The numbers 0 to 15 in o. are assigned only to monochrome characters. That is, in the table scr, when the character displayed at the position of a certain small area is a single color character, the palette number PNo. Is assigned to the small area in the same manner as the 2-bit mode or 1-bit mode character. , Character number C
Instead of No., 0 to 0 of the color conversion table of the palette
The color number of the color of the character among the 15 color numbers is assigned. Thereby, the color (single color) of the small area is determined. Therefore, for a single-color character, by registering and recording the color data of the character in the screen table scr as described above, it is not recorded as compressed image data for each character described later.

For the above-described single-color characters, the character numbers for the characters in the 2-bit mode and the 1-bit mode start from the 16th character. Originally, 10 bits are assigned to the character number,
There is ample room for such number shifts.

The data of the screen table scr is supplied to the recording processing means 38 as recording data.

Then, as described above, the sorting means 31
In the character-based image data sorted and rearranged in (1), N (N is an integer of 768 or less) character data C2 (0) to C2 (N-1) of each 2-bit mode character
Is supplied to the labeling means 33 via the register 32. In the labeling means 33, as shown in FIG. 16A, for each of the data C2 (0) to C2 (N-1) of the character in the 2-bit mode, a color number table of four or three colors of the character, Compressed image data dat2 (0) to dat2 (N-1) are formed from data of a 2-bit index number indicating each color number position on the color number table. Then, the compressed image data dat2 (0)
~ Dat2 (N-1) is temporarily stored in the register 34.

Similarly, M (M is 7)
The data C1 (0) to C1 (M-1) of each 1-bit mode character (an integer of 68 or less) are supplied to the labeling means 36 via the register 35. In the labeling means 36, character data C1 of each 1-bit mode
For (0) to C1 (M-1), as shown in FIG. 16B, a color number table of two colors of the character and data of a 1-bit index number indicating each color number position on the color number table are obtained. Compressed image data dat1 (0) to da
t1 (M-1) is formed. Then, the compressed image data dat1 (0) to dat1 (M-1) are temporarily stored in the register 37.

Then, all the compressed image data in the 2-bit mode from the register 34 and all the compressed image data in the 1-bit mode from the register 37 are supplied to the recording processing means 38 as recording data.

[Generation of Recording Data] The recording processing means 38 creates data to be recorded on a CD-ROM. That is, the data on the image of one frame described above is 2
Color conversion tables COL (0) to COL (COL) shown in FIG. 12 for the compressed image data relating to the pixels of each character in the bit mode and the 1-bit mode, and the eight palettes of one frame which are data other than the image data. 7)
And the screen table scr shown in FIG.

In the case of this example, the compressed image data for one frame to be recorded has, as shown in FIG. 17, a mode indicating the number of characters N in the 2-bit mode and the number M of characters in the 1-bit mode at the beginning. Number information and compressed image data dat2 (n) (n
= 0,1,2... N-1) and M pieces of compressed image data dat1 (m) (m = 0,1,2... M-1) of 1-bit mode characters. As described above, a single-color character has its color information registered in the screen table scr.
It is not recorded as pixel data.

The information for one character is shown in FIG.
As shown on the lower side of the figure, the information includes color number table information and index number data for 64 pixels. As shown in FIG. 16, the index number data corresponding to each pixel is 2 bits in the 2-bit mode and 1 bit in the 1-bit mode. In this case, since the number N of characters in the 2-bit mode and the number M of characters in the 1-bit mode change according to the content of the pixel, the data length of data for one frame of character pixels is variable.

In this example, the number of characters in each mode is recorded as mode number information. Instead of this mode number information, the last character of the 2-bit mode and the first character of the 1-bit mode are recorded. In the meantime, mode delimiter information of a bit pattern that does not occur as character data may be recorded.

In the above-described recording data, one frame is processed as one lump in this example, but the data recording mode on the CD-ROM naturally follows the data format of the CD-ROM. .

For example, the sectors when the recording mode of the CD-ROM is mode 1 are as shown in FIG. That is, a sync (synchronization) pattern is arranged at the head of a sector, and a header including a sector number and a track number is arranged subsequently. And after this header is 2K
Bytes of user data are provided, and the last is auxiliary data including codes for error detection and error correction of the user data.

In the case of this example, the above-described moving image data and other data are recorded in the user data area of the sector. The first 32 bytes of the 2K-byte user data are used as identification information ID. The identification information ID indicates what data is recorded in the user data area of each sector, and includes information indicating how many sectors of the same data continue. Of course, other information can be included in the identification information ID.

In the case of this example, the content of the data indicated by the identification information ID is, as described later, the user data of the sector is composed of image data of one moving image, a color conversion table, and a screen table scr. Information, background image data, foreground image data, other control data, and the like are prepared.

By the way, in the case of this example, the data amount relating to the moving picture compressed as described above can be as follows, for example, per frame.

Since there are 8 pallets per frame,
As a color conversion table, 16 (color) × 8 (palette) × 2 (byte) = 256 in total
(Bytes). Further, since the screen table scr has 2 bytes per character, 768 × 2 (bytes) = 1536 (bytes).

Therefore, the total data amount of the color conversion table and the screen table scr is 2 Kbytes or less and can be accommodated in one sector.

Further, since the moving image data has four kinds of color numbers represented by 4 bits in the character of the 2-bit mode, the color number table is 4 (bits) × 4 = 16 (bits). = 2 (bytes). Since the index number data is 2 bits, 2 (bits) × 64 = 128 (bits) = 16 (bytes). Therefore, one of the two-bit mode characters
The data amount per character is 18 bytes.

Since the color number of a character in the 1-bit mode may be two colors, the color number table is 4 (bits) × 2 = 8 (bits) = 1 (byte). Also, since the index number data is 1 bit, 1 (bit) × 64 = 64 (bit) = 8 (byte). Therefore, one of the 1-bit mode characters
The data amount per character is 9 bytes.

For monochromatic characters, each character
Since pixel data is not transmitted, one frame of image data
The compression ratio of 2 bits mode and 1 bit
The number of characters in single mode and the number of single color characters
Is determined by the ratio of For example, in the case of 2-bit mode: 1-bit mode: single color = 3: 3: 2 = 288: 288: 192, character pixel data 2-bit mode 288 × 18 = 5184 bytes1-bit mode 288 x 9 = 2592 bytes  The total is 7776 bytes, which is less than 8K bytes, so it fits within 4 sectors.
You.

From the above, in the case of this example, the CD-R
In the OM, as shown in FIG. 19, data relating to a moving image can be recorded as 5 sectors for each frame. That is, character data in the 2-bit mode and the 1-bit mode (mode number information is included in the first sector) are recorded as user data of the first 4 sectors out of 5 sectors. 19, which is indicated by hatching in FIG.
The data of the screen table scr and the color conversion table are recorded in the third sector.

As the 32-byte identification information ID of the user data area of each sector, the first four sectors include information indicating that the data is moving image data,
Information on the number of sectors that follow (4 in the case of the first sector) is recorded. In the last fifth sector, information indicating that the data is data of the screen table scr and the color conversion table, and information of the number of sectors following the data (in this case, 1) are recorded.

In this manner, data relating to a moving image for one frame is repeatedly recorded every five sectors. In the case of this example, considering that the transmission rate of the CD-ROM is 150 Kbytes (75 sectors) / sec, 1
A moving image of 5 frames (frames) / second can be recorded or reproduced.

It should be noted that, in addition to the above-described compressed image information, a program for decoding the compressed image information and a game program are recorded on the CD-ROM. Further, audio information is also appropriately recorded. As a decoding program, a 2-bit mode decoding program and a 1-bit mode decoding program are recorded. Also, a character rearranging program is recorded.

These program data are recorded separately from the above-described data, and can be read out at a time of decoding and prior to reproduction of a moving image or the like. These program data can also be recorded as data other than the image data of the moving image in the above example in the middle of the moving image data in 5-sector units in the same manner as the still image recording method described later. .

According to the data compression method described above, 1
Since the image is hierarchically divided into small regions on a frame-by-frame basis and the vector data is subjected to the image data of each layer, the compression rate of the image data can be increased.

In this case, one group (palette) is formed by grouping characters having similar colors, a plurality of groups are formed for one screen, and image data is divided into pallets (groups). I have. And
Since the vector quantization processing is performed in the palette including the image parts of similar colors, the quantization error is reduced.

Further, at the time of decoding, since the decoding process can be performed only by referring to the table, the configuration of the decoder is simplified. Further, since a large-capacity buffer memory is not required, a general-purpose DSP having a limited capacity of the built-in RAM can be used as a decoder, and the cost of the decoder can be reduced.

Further, since the compression processing is performed without using the frame correlation, even if an error occurs during decoding, the error is completed within one frame and does not affect subsequent frames.

Further, since the decoder circuit can be provided at low cost and a CD-ROM can be used as a recording medium, it is effective when applied to software of a computer game machine.

In the above example, the data of the character having one color is stored in the screen table scr.
, And only the color data is transmitted, and the data on a pixel-by-pixel basis is not transmitted, so that the traffic on the data transmission path can be reduced.

In the above example, the vector quantization by the vector quantization means 24 is performed by S / N in each frame.
Is maintained constant in all frames so that the maximum value Emax of the quantization error in the character is kept constant. For this reason, the data size after quantization changes according to the information amount of a frame (complexity of image content).

However, by quantizing each character as follows, the data amount (data transmission rate) for each frame can be kept constant or less.

That is, first, a threshold value Eθ of a distance that brings together pixels of similar colors in a character.
Is set, and vector quantization is performed for each character based on the threshold value. That is, for the image data in each character, the quantization error
Vector quantization is performed until just before exceeding θ. By this quantization, data of a character having a large color change is subjected to data compression so as to have four colors. Further, in a character having a flat color change, the number of colors is reduced, and some characters become three colors, two colors or one color.

When the vector quantization process is completed for all the characters in one frame, the maximum value Emax of the quantization error in all the characters in one frame is calculated. Next, the number N of characters in the 2-bit mode, the number M of characters in the 1-bit mode, and the number L of single-color characters in one frame are counted. Next, these numerical values N, M, L
To calculate the image data amount per frame. The calculation of this pixel data amount is as follows.

Data amount of one frame = N × 18 (bytes) + M × 9 (bytes) + L × 0 Whether or not the resulting data amount of one frame is equal to or smaller than a predetermined value, and therefore, the compression ratio is set to a predetermined value It is determined whether the data amount is equal to or smaller than a predetermined value.
The threshold value Eθ is set to the maximum value Ema of the quantization error.
Set to x and repeat the above vector quantization process.

As described above, the vector quantization is repeated by changing the threshold value Eθ until the data amount per frame becomes equal to or less than the predetermined data amount. In such a case, the S / N differs for each frame, but the amount of transmission data is constant. That is, in the case of a moving image to be described later, the number of frames (frames) per second can be constant.

The processing unit for dividing the pallet is 1
Instead of frames, a plurality of frames may be used to perform three-dimensional palette division.

[Description of Decoding Apparatus as One Embodiment of Image Display Apparatus of the Present Invention] Next, the present invention is applied to an apparatus for decoding image data compressed as described above and recorded on a CD-ROM. A case of a game machine as an example of the case where the present invention is applied will be described.

FIG. 20 shows an example in which the present invention is applied to a game machine using a microcomputer, wherein 1 is the game machine body, 4 is a sub-processing section, and 5 is
A D-ROM, 6 is a program cartridge, and 7 is a main processing section for audio data.

The main body 1 of the game machine is constituted by a microcomputer.
Denotes a DMAC (DMA controller), 13 denotes a RAM for a work area, 14 denotes a PPU (Picture Processing Unit), and 15 denotes a video RAM.

Then, the game machine main body 1 includes the first and second game machines.
2 bus configuration including the system buses 18 and 19 of FIG. The two system buses share a data bus, but have an address bus that is a first system bus and a second system bus.
System bus. And DMAC
12 allows DMA transfer only between the first and second system buses 18 and 19.

In this case, the CPU 11 and the second system bus 19 are connected via the port 16 and the CPU 1
The device connected to the first and second system buses 19 can be accessed via the port 16.

The first system bus 18 has a CPU 1
1, the DMAC 12 and the RAM 13 are connected. Also,
The DMAC 12 and the PPU are connected to the second system bus 19.
14 is connected and a video RAM is
15 and the CRT display 6 are connected. The sub-processing unit 4 and the main processing unit 7 for audio data are connected to the second system bus 19.

In this case, the video RAM 15 is divided into a plurality of memory areas M1 to M4, for example, as shown in FIG. In this case,
Each of M1, M2 and M3 is a memory area (memory plane) for reproducing one image. Each of these memory areas M1 to M3 corresponds to two frames (2
Screen area), and image data of one of the screen areas is transferred to the CRT display 8 by the PPU 14.
Are read out in synchronization with the vertical and horizontal scanning of the image, and displayed as an image on the display 8, and while this display is being performed, the image data of the image to be displayed next is written in the other screen area. .

In this example, as will be described later, the memory area M1 is used as a memory area for an image in the case of one moving image and also as a memory area for a background image. The memory area M2 is used as a memory area for a foreground image.

The memory area M4 is a work area of the PPU 14, and is used as a screen table scr, a color conversion table, and other data areas.

Further, in the audio data main processing section 7 of the game machine main body 1, reference numeral 71 denotes its APU (audio processing unit), reference numeral 72 denotes a D / A converter,
Reference numeral 3 denotes an audio output terminal. The APU 71 is connected to the bus 19 and connected to the D / A converter 72. When audio data and a decoding program for the audio data are loaded into the APU 71, the audio data is decoded into a digital audio signal, and the digital audio signal is D / A converted into an analog audio signal by the converter 72, and then output to the output terminal. 73 is output.

The sub-processing unit 4 has a CD player to enable the use of the CD-ROM 5,
1 is the CD player, 42 is the DSP, 43 is the CD-R
OM decoder, 44 is RAM for the work area, 4
5 is a controller. The audio data and the image data are recorded on the CD-ROM 5, and the audio data and the image data, especially the image data, are recorded by being compressed as the image data by the above-described method.

The DSP 42 corrects errors in the reproduction signal of the player 41 and separates user data such as image data and control data such as a track number from the reproduction signal.
5 is the control data from the DSP 42 and the CPU 11
Control the player 41 based on the instruction data from
This is for reproducing target data. Also,
The decoder 43 outputs the playback signal of the player 41 to a CD-RO
In the case of an M5 reproduction signal, this is for performing processing such as error correction for the CD-ROM.

Further, in the sub-processing unit 4, 50 is DS
P, which is a general-purpose DSP, performs processing of image data. Although the sub-processing unit 4 is integrated with the game machine main body 1 in this example, it may be in the form of an adapter with respect to the game machine main body 1. Although not shown, the DSP 50 includes a program RAM and a buffer RAM (which can be constituted by one RAM).

The program cartridge 6 is used by being inserted into the slot 2 of the game machine body 1 when using the game machine. When the CD-ROM 5 is not used, the program cartridge 6 for general game software is inserted, and the program cartridge 6 is inserted into the CD-ROM 5.
When using 5, a special one is inserted.

The cartridge 6 has the ROM 61
And a RAM 62, and in the case of a cartridge for a CD-ROM 5, the ROM 61 includes a CD-ROM 5
A program for a so-called initialization process for causing the game machine main body 1 to take in the recorded data and execute the game is written. The RAM 62 is used, for example, when temporarily interrupting the game in the middle of the game, for holding various data relating to the state at that time until the game is restarted, and is backed up by the battery 63.

When the cartridge 6 is inserted into the slot 2 of the game machine main body 1, the ROM 61 and the RAM 62 are connected to the bus 18 via a connector (not shown).

Then, the program in the ROM 61 of the cartridge 6 is executed by the CPU 11 and the CD-ROM 5
Is taken into the RAM 13 of the game machine body 1, and the decoding process of each user data is performed based on the identification information ID in the user data of each sector. Thereby, a moving image is displayed.

That is, the CD-player 41
When the data is reproduced from the ROM 5, the reproduced data is sequentially supplied from the player 41 to the DSP 42 and the decoder 43 to perform processing such as error correction, and the error-corrected data is transmitted from the decoder 43 to the DMAC 12 by the DMAC 12. DMA in the first buffer area of the RAM 13
Will be transferred.

Next, the CPU 11 checks the identification information ID of each sector of the data fetched into the RAM 13. According to the check result, the CPU 11
Executes a decoding procedure corresponding to the reproduction data of the content indicated by each ID.

The decoding program and the game program described above are loaded into the RAM 13 from the CD-ROM 5 prior to reproduction of image data and the like.

[Decoding Process for Moving Image When Not Divided into Background and Foreground] As a result of checking the identification information ID in the CPU 11, it is determined that the contents of the user data in the sector are image data of one moving image. Then, the moving image is decoded and displayed in the following manner.

That is, decoding processing is performed on data of five sectors including one frame of compressed image data as follows. The procedure for decoding the moving image data basically includes the following three steps.

A. B. For each character, referring to the color number table, convert the 2-bit or 1-bit index number data into 4-bit color number data of the color conversion table COL (j). B. For each pixel of the character of each palette, refer to the color conversion table of the palette, and convert the color number data decoded in section A into actual color data. Step of rearranging the sorted characters, that is, B
Rearranging the pixel data decoded by the term to the original character position DSP 50 performs the step of the term A among the steps of the terms A to C, and the steps of the terms B and C
U14 does.

[1A Step] First, the DSP 50 decodes the user data of four sectors including the compressed image data of one frame into the data of the color number as follows. Video RA
The procedure up to writing in the memory area M1 of M15 will be described. That is, (1) A program for decoding a 2-bit mode character is loaded from the RAM 13 to the DSP 50.

(2) Of the character data in the 2-bit mode of the image data DMA-transferred to the first buffer area of the RAM 13, eight characters from the head thereof are DMA-transferred to the DSP 50 by the DMAC 12.

(3) In the DSP 50, the step of item A is executed by the program of (1), and the index number data transferred by DMA is converted into color number data (FIG. 16A) by the color number table. By this conversion, the index number data (=
18 bytes x 8) is 4 bits x 8 pixels x 8 pixels (= 25
(6 bytes) color number data.

(4) The decoded color number is
AC12 stores D in the second buffer area of RAM13.
MA transfer is performed.

(5) Thereafter, the processing of (2) to (4) is repeated, and all the index number data of the character in the 2-bit mode are decoded into color numbers and DMA-transferred to the second buffer area of the RAM 13. You.

(6) The data of all the color numbers of the 2-bit mode DMA-transferred to the second buffer area of the RAM 13 are transferred to the video R through the PPU 14 by the DMAC 12 during the vertical blanking period of the CRT display 8.
The data is DMA-transferred to the AM 15 and written to the memory area M1.

(7) When the processes up to (6) are completed, a program for decoding 1-bit mode characters is loaded from the RAM 13 to the DSP 50.

(8) Of the 1-bit mode character data of the image data DMA-transferred to the first buffer area of the RAM 13, eight characters from the beginning of the data are DMA-transferred to the DSP 50 by the DMAC 12.

(9) In the DSP 50, the step of item A is executed by the program of (7), and the index number data transferred by DMA is converted into color number data (FIG. 16B) by the color number table. By this conversion, the index number data (=
9 bytes x 8 pixels are 4 bits x 8 pixels x 8 pixels (= 25
(6 bytes) color number data.

(10) The decoded color number is
AC12 stores D in the second buffer area of RAM13.
MA transfer is performed.

(11) Thereafter, the processes of (8) to (10) are repeated, and all of the index number data of the 1-bit mode character is decoded into color number data, and
13 is DMA-transferred to the second buffer area.

(12) The data of all the color numbers in the 1-bit mode DMA-transferred to the second buffer area of the RAM 13 are transferred to the video R through the PPU 14 by the DMAC 12 during the vertical blanking period of the CRT display 8.
The data is DMA-transferred to the AM 15 and written to the memory area M1.

The DMA transfer of the 2-bit mode color number in (6) can be performed immediately before (12) (between (12) and (11)).

[2. Steps B and C] (13) When the processing up to the step (12) is completed, the fifth sector of the image data of one frame is processed. That is, CPU
Reference numeral 11 indicates that the fifth sector is a data sector of the screen table scr and the color conversion table based on the identification information ID. Therefore, the CPU 11
The data of the screen table scr and the color conversion table DMA-transferred to the first buffer area of M13 are DMA-transferred to the video RAM 15 through the PPU 14 by the DMAC 12 without passing through the DSP 50. In this case, the data of the screen table scr and the color conversion table are written in the memory area M4 of the video RAM 15.

(14) When the above transfer processing is performed, the PPU
14 executes the steps of the above-mentioned B and C terms in real time. That is, by referring to the color conversion table COL (j), the data of the color number of the memory area M1 processed by (2) to (5) and (8) to (11) is converted into the pixel data of the actual color. , And by referring to the screen table scr, the pixel data of each character is written to the address corresponding to the original character position.

(15) When one frame of pixel data is written to one screen area of the memory area M1 of the video RAM 15 as described above, the display area of the video RAM 15 is switched to that screen area, and the pixel data is written. The activated area is activated, and its screen is displayed on the display 8.

(16) The process returns to (1), and thereafter, the processes of (1) to (16) are repeated for each frame.

The image data reproduced from the CD-ROM 5 is stored in the RAM 13 and the DSP 50 as described above.
And the PPU 14 are successively sent to the video RAM 15 while being processed in a pipeline processing. Therefore, an image based on the image data of the CD-ROM 5 is displayed on the display 8 as a moving image. This moving image display can be performed at a rate of 15 frames / second as described above.

As described above, according to the example shown in the figure, the CPU 11 manages all data flows, so that the reading of image data from the CD-ROM 5 and the CPU
Since the CPU 11 absorbs the asynchronism with the processing in step 11, the image data can be continuously read from the CD-ROM 5. Moreover, the configuration for this is simple as is clear from FIG.

The DSP 50 performs the primary decoding and the PPU 14 performs the secondary decoding on the image data of the moving image that has been subjected to the data compression. Can be used, and the cost can be reduced.

Further, since the decoding of the image data which has been compressed is separately performed by the DSP 50 and the PPU 14, the image data can be decoded at a sufficient speed, and a moving image with a sufficient motion is displayed. be able to.

Further, the RAM 13, the DSP 50, and the PP
Since the DMAC 12 transfers data to and from the U 14, it does not impose a load on the CPU 11. In addition, DSP50
During the decoding, the CPU 11 is idle, so that other data processing instructions can be given.

[Encoding of Moving Image When Divided into Background and Foreground] Next, an example of an encoding method used in a method of transmitting image data according to the present invention and a recording method on a CD-ROM will be described. In the example described below,
The above-described animation of 15 frames / second can be displayed as a composite image of the background and the foreground.

FIGS. 1 and 2 are functional block diagrams for explaining the flow of image data and the flow of encoding processing in this example. This corresponds to a flowchart of the processing in the case of performing the computer processing.

In this example, as an example of an image to be switched and displayed according to the correspondence of the user, as shown in FIG. 3A,
An image VA of the flight pattern 96 of the enemy aircraft and an image VB of the explosion pattern 97 will be taken as an example. In this case, as is clear from the figure, since the image is a moving image, the patterns 96 and 9 in the images VA and VB are respectively displayed in the (n-1) th frame, the nth frame, and the (n + 1) th frame.
7 are different in size, and the size of the pattern 96 and that of the pattern 97 correspond to each other.

When such images VA and VB are prepared, when the image VA is displayed, for example, when a user's attack succeeds in the (n-1) th frame, n-
By switching to the image VB of the first frame, an image having a natural feeling can be obtained, and an image having excellent interactivity can be obtained.

In the present invention, in order to obtain the two images VA and VB at the time of reproduction, the original image of the moving image is divided into a background image and a foreground image. That is, in this example, as shown in FIG. 4, the original image VA is divided into a background image BG and a foreground image Va consisting of only the flight pattern 96 excluding the background image BG, and the original image VB
Is divided into an image BG of the same background and an image Vb of the foreground consisting of only the explosion pattern 97 excluding the image BG of the background.

In the encoding process of this example, two original images VA and VB as shown in FIG. 3 and an image BG of the background are prepared. In FIG. 1, the original images VA and VB are foreground clipping means 101A.
And 101B, and the background image BG is supplied to the foreground clipping means 101A and 101B. These foreground clipping means 101A and 10A
1B, the original images VA and VB and the background image BG
Is obtained, and foreground images Va and Vb as shown in FIG. 4 are obtained.

These foreground images Va and Vb are supplied to encoding means 200A and 200B, respectively.
After the data is compressed, the packing means 10 is used for recording.
At 2, packing is performed as described below.

FIG. 2 shows encoding means 200A and 200A.
In an example of a specific configuration of 0B, foreground image data Va and Vb from foreground clipping units 101A and 101B are supplied to character clipping units 201A and 201B, respectively. In this case, the encoding means 200A and 200A
00B has exactly the same configuration.

In general, foreground images Va and V
b, the area occupied by the pattern images such as the flight pattern 96 and the explosion pattern 97 on the screen is small, and in this example, since the background image is transmitted separately, all of the foreground images Va and Vb for one screen are included. There is no need to transmit.

Therefore, in this example, the character cutout means 201A and 201B first set a rectangular frame area SPFL including a flight pattern 96 and an explosion pattern 97, respectively, as shown in FIG. 5A, for example. Is extracted. Next, as described above, the image of the rectangular frame area SPFL is
It is divided into characters of dot size × 8 dots.
The size of the rectangular frame area SPFL is, for example, the size of an integer number of characters.

Next, in the character cutout means 201A and 201B, as shown in FIG. 5B, the image component of the target flight pattern or the image component of the explosion pattern among the characters in the rectangular frame area SPFL is included. Only characters are extracted as output characters. For example, in the case of the flight pattern as shown in FIG. 5, only the characters A1 to A16 are extracted as output data of the character extracting means 201A as shown in FIG. 5B.

Next, the output data of the character extracting means 201A and 201B are supplied to the foreground image data and position data generating means 202A and 202B, respectively. Then, in these generating means 202A and 202B, the rectangular frame area SPFL of the foreground images Va and Vb
As position data in the display screen, for example, as shown in FIGS. 5A and 5B, the horizontal direction (X direction) and the vertical direction (Y direction) of the upper left corner of the rectangular frame area of each of the images Va and Vb are displayed.
Direction) (XA, YA) and (XB, YB). In this case, the coordinate data is, for example, the origin (0, 0) at the upper left corner of the display screen, and each coordinate value represents the distance in the X and Y directions from this origin in, for example, a value in units of dots. It is expressed.

In the generating means 202A and 202B, coordinate data ZA and ZB in the depth direction (Z direction) of the foreground images Va and Vb are determined. The coordinate data ZA and ZB in the depth direction are determined, for example, as depth. For example, in the case of the image pattern in the original image in the example of FIG. 3, the smaller the size of the pattern is, the deeper it is considered, the larger the coordinate value Z is. Determined.

The generating means 202A and 202B generate the position data DFa and DFb of the foreground images Va and Vb as shown in FIG. 5C based on the data obtained as described above. In this case, for example, the position data DFa includes the identification data ID of the foreground image Va (“0” in the illustrated example) and the coordinate data (X of the reference position on the screen of the foreground image Va).
A, YA), the Z direction coordinate data ZA of the foreground image Va, and the size (= 4) which is data of the number of characters cut out as the foreground image Va. The position data DFb includes identification data ID (“1” in the example in the figure) of the foreground image Vb, coordinate data (XB, YB) of the reference position on the display screen of the foreground image Vb, and the foreground image Vb. And the size (= 7) which is data of the number of characters cut out as the foreground image Vb.

Then, from the foreground image data and position data generating means 202A, the cut-out character data SCa and the position data DFa are obtained. Also, foreground image data and position generation means 202B
From the character data SCb of the extracted character.
And the position data DFb.

The data SCa and SCb in character units and the position data DFa and DFb of these foreground images Va and Vb are respectively converted into data compression means 203A,
203B.

The data compression means 203A, 203B
Then, compression processing using vector quantization is performed on the data SCa, SCb in character units of the foreground images Va, Vb in the same manner as described above. However, in the case of this example, assuming that the foreground image data SCa, SCb is composed of, for example, characters as shown in FIG. 6A, each of the characters A0 to A3, B0 to B6 is, for example, 2 characters.
It is compressed to bit mode data.

Data compressed foreground images Va and Vb
Are supplied to sorting and coordinate table generating means 204A and 204B, respectively. This generating means 204
A, 204B, each character A0-A3, B0-B
As shown in FIG. 6B, the compressed data of No. 6 is sequentially shifted to the left and sorted, and sorted data OBCa, OB
Obtain Cb.

In the generating means 204A and 204B,
The coordinates (XA, YA) of the reference position of each foreground image Va, Vb
), (XB, YB) are set to the origin (0, 0), respectively, and the X coordinate tables OBXa, OBXb of the characters A0 to A3, B0 to B6, and the characters A0 to A6
Y coordinate tables OBYa, OBYb of A3, B0 to B6
Are formed as shown in FIG. 6B. In this case, each coordinate value is represented by the number of dots from the origin, as described above.

The sort data OBCa, OBCb
And the X coordinate tables OBXa and OBXb and the Y coordinate tables OBYa and OBYb are supplied to the packing means 102. In this packing means 102, as shown in FIG. 6C, image data OBJP obtained by sequentially sorting the image data of the characters A0 to A3 and B0 to B6 of the two foreground images Va and Vb, and the two foreground images Va and Vb. Images Va, V
The X coordinate table OBJ (x) in which the X coordinate tables OBXa and OBXb of the respective characters A0 to A3 and B0 to B6 are sequentially sorted, and the characters A0 to A3 and B0 to B6 of the two foreground images Va and Vb Y coordinate table OB
Y coordinate table OBJ in which Ya and OBYb are sequentially sorted
(Y).

The image data OBJP, the X coordinate table OBJ (x), and the Y coordinate table OBJ (y) are supplied to the recording data generating means 103 as shown in FIG. Note that the foreground image data and the reference position data DF from the position data generation means 202A and 202B are provided.
a and DFb are supplied to the packing means 102, and these reference position data DFa and DFb are also supplied to the recording data generating means 103.

The background image BG is the switch circuit 1
04 is supplied to one input terminal a. The switch circuit 104 is alternately switched to the input terminals a and b for each frame by a switching signal SW. The other input terminal b of the switch circuit 104 is a non-signal input. Therefore, from the switch circuit 104, only one frame, for example, an odd frame image is obtained for every two frames of the background image BG.

The odd frame image data of the background image BG from the switch circuit 104 is
The compression processing is performed by the two-stage vector quantization as described above, and the 2-bit mode and 1-bit mode character data, the screen table s
Image data composed of the data of cr and the color conversion table COL (j) is formed.

The background image data from the encoding means 105 is supplied to a two-way dividing circuit 106.
In the two-division circuit 106, one frame of the background image data (including the screen table scr and the color conversion table) is divided into half. Then, each half of the data is supplied to one and the other input terminals a and b of the switch circuit 107, respectively. This switch circuit 10
7 is switched in synchronization with the switch circuit 104 by the switching signal SW.
For example, during the odd frame period, the first half of one frame of the background image data is obtained, and during the even frame period, the second half of the one frame of the background image data is obtained. . The output of the switch circuit 104 is supplied to the recording data generation unit 103.

The color conversion table indicates that the number of colors used in the background image and the foreground image is 8 (palette) × 16 (color) =
If it is 128, it can be used in common. That is, a color number for the common color conversion table may be registered as data of the color number table of the character data.

Then, the recording data generating means 103
As data to be recorded as five sectors of a CD-ROM,
Print data is generated that is composed of half the data of the background image BG of one frame and the data of one frame of the two types of foreground images Va and Vb.

That is, FIG. 7 shows an example of recording data. In the case of the example shown in FIG. 7, in the five sectors of the odd-numbered frame, the first half of one frame of the background image BG is reached by the middle of the first two sectors. 1/2 of the data is arranged,
By the following four sectors, two kinds of foreground images Va and Vb
, And then control data. The control data includes a table of the Z coordinate of each character of the background image BG and the foreground images Va and Vb described above.
Are disposed.

In the five sectors of the even-numbered frame, half the data of the latter half of one frame of the background image BG is arranged halfway through the first two sectors. Others are the same as the five sectors of the odd frame.

In the case of this example, the Z coordinate table of each character of the background image BG is divided into one frame, and the last sector of the five sectors of the odd frame and the last sector of the five sectors of the even frame are divided. It is divided and distributed. Depending on the data arrangement method, for example, a Z-coordinate table for one frame may be arranged only in even-numbered frames.

Since the data structure is as described above, FIG.
, The 32-byte identification information ID of each sector includes the following information. That is, the identification information ID of the first one of the five sectors corresponding to the image of the odd-numbered frame includes information indicating that there is data in the first half of one frame of the background image data of the moving image, and the even-numbered frame. In the identification information ID of the first one of the five sectors corresponding to the first and second sectors, information indicating that the data is the latter half of one frame of the background image data of the moving image (including the screen table scr and the color conversion table). Is included.

The identification information ID of the second sector of the five sectors corresponding to the odd frame and the even frame includes information indicating the background and foreground image sectors. Information ID for identification of sector
Contains information indicating that the data is a sector of the data of the foreground image, and the identification information ID of the fifth sector includes information indicating that the data is control data.

At the beginning of the data of the odd-numbered frame and the even-numbered frame which are １ ／ of the data of the background one frame, the number of character data N1 and N2 in the 2-bit mode are respectively set
And the number of character data M1 and M2 in the 1-bit mode are recorded. In this case, when the background data of the odd-numbered frame includes the character of the 2-bit mode and the character of the 1-bit mode, the background data of the even-numbered frame that is paired with the character has only the character data of the 1-bit mode. When the background data of the even-numbered frame includes a character of the 2-bit mode and a character of the 1-bit mode, the background data of the odd-numbered frame corresponding thereto includes only the character data of the 2-bit mode.

The boundary between the 2-bit mode and 1-bit mode characters of the background image data and the boundary between the character data and the data in the screen table scr or the color conversion table can be determined from the information on the number of character data.

The data of the foreground images Va and Vb are
As shown in FIG. 7, the aforementioned image data OBJP and X
Coordinate table OBJ (x) and Y coordinate table OBJ
(Y) and, in this case, a color conversion table for the images Va and Vb. In the example of FIG. 7, the X coordinate table OBJ (x) and the Y coordinate table O
BJ (y) records an X coordinate table and a Y coordinate table of each of the foreground images Va and Vb as a pair. In this case, also in the data of the foreground image, information on the number of characters included in the image data OBJP is inserted, for example, at the beginning.

The number of characters in the image data of the background image BG and the image data OBJ of the foreground images Va and Vb
Instead of recording the number of characters of P, a flag indicating that is inserted between the background image and the foreground image,
A flag indicating this may be inserted between the foreground image and the coordinate data and at the boundary between the screen table scr.

As described above, the recording data composed of the background image data and the data of the plurality of foreground images is stored in the CD-ROM as the unit recording data amount of five sectors.
It is recorded repeatedly for each sector. However, the background image B
For G data, data for one frame is transmitted every 10 sectors.

Therefore, by reproducing this CD-ROM in the same manner as described above and decoding the reproduced data,
A foreground moving image of 15 frames / second is displayed in a background image of a 7.5 frame / second moving image. Therefore, the data of the background image BG is in a frame-dropped state, but the background is generally less noticeable to the viewer than the foreground and is not so noticeable. Hereinafter, a decoding method in this case will be described.

[Decoding of Moving Picture of Background and Foreground] In this example, the decoding and display processing of the foreground images Va and Vb are performed every 5 sectors, and the foreground has 15 frames / frame.
Although the reproduction of a moving image of seconds is performed, the background image BG is completed when 10 sectors corresponding to two frames of the odd frame and the even frame are reproduced.
A moving image is reproduced at 5 frames / sec. For this reason, the decoding process for the five sectors of the odd-numbered frame is slightly different from the decoding process for the five sectors of the even-numbered frame that is a pair with the decoding process.

First, in this case, the R-ROM is read from the CD-ROM.
When processing five sectors of odd frames of image data DMA-transferred to the AM 13, the background is determined from the information on the number of character data N1 and M1 in the 2-bit mode and 1-bit mode for the background image, if any. Of the image data of the foreground and the image data of the foreground.
Further, a boundary between the image data of the moving image of the foreground and the control data is known from the information on the number of character data pieces for the image of the foreground. Further, the boundary between the image data and the coordinate data as the position data is known from the information on the number of characters of the foreground moving image.

From the boundary of these data, RA
With respect to the step of the item A for the data transferred to M13, the processing is switched from the decoding processing of the background image to the decoding processing of the foreground image. Then, control data is taken in, and image reproduction processing is performed on the foreground image. Then, the foreground image is combined with the background image reproduced and displayed so far.

Also, DM from the CD-ROM to the RAM 13
A When processing five sectors of an even-numbered frame of the transferred image data, the background image is determined from the information N2 and M2 of the 2-bit mode and 1-bit mode character data, if any, on the background image. The remaining image data for one frame and the screen table s
Know the boundary between cr and the data of the color conversion table. Then, for example, the boundary between these and the data of the foreground image based on the boundary flag is known. Further, a boundary between the image data of the moving image of the foreground and the control data is known from the information on the number of character data pieces for the image of the foreground. further,
From the information on the number of characters of the foreground moving image, the boundary between the image data and the coordinate data as the position data and the color conversion table are known.

In the reproduction of the even-numbered frame, the background is switched to the newly decoded image, and the decoded foreground image is combined with the new background image to form a display image, which is displayed on the display. You.
The above will be described in more detail.

[Decoding of Data of 5 Sectors of Odd Frame] (1) A program for decoding a character in the 2-bit mode is read from the RAM 13 by the DSP.
50 is loaded.

(2) The 2-bit mode character data of the background image data among the image data DMA-transferred to the first buffer area of the RAM 13 is a DMAC.
12, the data is DMA-transferred to the DSP 50 and decoded into color number data.

(3) The decoded color number corresponds to the DM
AC12 stores D in the second buffer area of RAM13.
MA transfer is performed.

(4) All the 2-bit mode color number data included in the 5 sectors of the odd-numbered frame of the background image data DMA-transferred to the second buffer area of the RAM 13 are stored in the CRT display 8. In the vertical blanking period, the DMAC 12 DMA-transfers to the video RAM 15 through the PPU 14 and writes it to the memory area M1.

(5) When the processing up to (4) is completed, if the background image data in the five sectors of the odd-numbered frame includes 1-bit mode character data, the 1-bit mode character Is loaded from the RAM 13 to the DSP 50.

(6) The 1-bit mode character data included in the sector of the odd frame of the background image data DMA-transferred to the first buffer area of the RAM 13 is DMA-transferred to the DSP 50 by the DMAC 12 and the color number Is decoded.

(7) The decoded color number is
AC12 stores D in the second buffer area of RAM13.
MA transfer is performed.

(8) The data of all the color numbers of the background 1-bit mode DMA-transferred to the second buffer area of the RAM 13 are transferred to the video RAM 15 through the PPU 14 by the DMAC 12 during the vertical blanking period of the CRT display 8. The data is DMA-transferred and written into the memory area M1.

(9) Next, according to the user's response, the CPU
11 determines which of the two foreground images Va and Vb is to be selected. Then, the image data of the selected foreground image, for example, the image Va, is read from the RAM 13,
The processes (1) to (4) are performed, and the foreground image Va
The data obtained by converting the data of all the characters A0 to A3 into the data of the color numbers are written in the memory area M2 of the video RAM 15.

(10) When the processes up to (9) are completed,
The CPU 11 transmits the X and Y coordinate tables OBXa and OBYa for the image Va of the X coordinate table OBJ (x) and the Y coordinate table OBJ (y), and the data and control data of the foreground color conversion table to the DSP 50. DMA transfer is performed by the DMAC 12 through the PPU 14 to the video RAM 15 without communication. In this case, the data of the coordinate table and the color conversion table and the control data are written in the memory area M4 of the video RAM 15.

(11) When the above transfer processing is performed, the PP
U14 executes the steps of the above-described items B and C for the image data of the foreground Va. That is, by referring to the color conversion table, the characters A0 to
The data of A3 is decoded into pixel data of an actual color. Then, the X coordinate XA1 and the Y coordinate YA1 of the position data DFa in the control data are referred to, and the position on the screen of the upper left corner of the original rectangular frame area (see FIGS. 3A and 3B) of the selected foreground image Va is referred to. Is determined.

(12) The X-coordinate table OBXa and the Y-coordinate table OBYa for the foreground image Va are referenced with the position of the upper left corner of the determined rectangular area of the foreground image Va as the origin. Foreground image Va
The positions of the characters A0 to A3 on the screen are determined,
Each of the characters A0 to A3 is written to a corresponding position in the memory area M2. At this time, the image portions that are not transmitted as the foreground image Va are all rendered as image data that is transparent.

(13) As described above, when one frame of the selected foreground moving picture Va is written into the memory area M2, the background from the area which is active for display in the memory area M1 of the video RAM 15 is displayed. As shown in FIG. 8, the image BG and the foreground image Va from the memory area M2 are combined, and the combined image is displayed on the display 8. At this time, the background used in the previous frame is used.

In this case, the Z coordinate ZA of the position data DFa of the selected foreground image Va is compared with the Z coordinate ZBG of the background data BG in the depth direction of each character.
In a state in which only the characters in the portion of ZA> ZBG among the characters of the foreground image Va are displayed in the background image, that is, only the characters determined to be in front are displayed.
The background and the foreground image Va are combined.

[Decoding of Data of Five Sectors of Even Frame] (1) When the five sectors of the even frame are reached, first, the background image data is the same as when the remaining image data of one frame is an odd frame. , And is written following the memory area M1 of the video RAM 15.

(2) When the transfer processing of one frame of the background image data to the memory area M1 of the video RAM 15 is completed, the CPU 11 sets the screen table scr of the background image in the first buffer area of the RAM 13 and the color conversion. The data of the table COL (j) is DMA-transferred by the DMAC 12 to the video RAM 15 through the PPU 14 without passing through the DSP 50. In this case, the data of the screen table scr and the color conversion table are written in the memory area M4 of the video RAM 15.

(3) When the above transfer processing is performed, the PP
U14 is the same as B described above for the image data of the background moving image.
The steps of item C and item C are executed.

That is, by referring to the screen table scr and the color conversion table COL (j), the data of the color number which is the image data of the background of the memory area M1 is decoded into the pixel data of the actual color.
Pixel data of each character is written to an address corresponding to the original character position.

Thus, the new background image is stored in the memory area M1.
, One of the memory areas M1 becomes active for display, and the background image is switched.

(4) When the transfer of the screen table scr and the color conversion table data for the background image data to the video RAM 15 is completed, even in this even-numbered frame, the selected foreground image data is converted to the odd-numbered frame described above. The decoding process is performed in the same way as
The data is written to one of the memory areas M2 of the video RAM 15. When the writing of one frame of the foreground image into one of the memory areas M2 is completed, the one memory area becomes active for display, and the new background image and the foreground image are displayed. The images are synthesized in the same manner as described above and displayed on the display 8.

(5) The processing returns to the processing of the odd frame.
Thereafter, the above processing is repeated in units of 10 sectors.

As described above, the display 8
A composite image in which the moving image of the background and the foreground is composited is displayed.
In this case, as the foreground image, a plurality of screens to be switched according to the correspondence of the user, for example, the flight pattern of the enemy aircraft and the explosion pattern thereof are prepared, and which is displayed on the decoding side as the foreground. Just choose what you want to do and it switches instantly. Therefore, a game machine having both interactiveness and entertainment can be realized.

Since the plurality of foregrounds are transmitted by using the portion where the background is dropped, it is not necessary to increase the compression ratio for transmission, and the deterioration of image quality can be reduced. Also, as in the above-described example, the number of characters that must be actually transmitted in the foreground can be reduced, and in this regard, data compression processing such as more efficient quantization processing is performed on the foreground image data. There is no need to perform this, and it is possible to minimize the deterioration of image quality.

Further, in this case, the moving picture of the foreground is 15 frames /
It can be an animation of seconds, and it will be an animation of smooth movement. On the other hand, the background is an animation of dropping frames compared to the foreground, but has little visual effect considering that human attention is directed to the foreground.

In this case, the background and foreground images are
Since both are moving images, a moving image screen with a sense of depth and a three-dimensional effect can be obtained.

By preparing a plurality of position data of the foreground image and selecting the position data for each image on the decoding side, a plurality of patterns of appearance positions of the foreground can be obtained. In this way, a game with a change can be enjoyed.

In the above example, the foreground image is compressed to 2-bit mode character data. However, as in the case of the background moving image, the foreground image is compressed to 1-bit mode and monochrome character data. Well, of course. The data compression method is not limited to the method using vector quantization as described above, and it goes without saying that various data compression methods can be used.

Further, as for the background image, one frame may be transmitted for three or more frames, instead of transmitting one frame for every two frames as in the above example.

Note that the background image may be a still image. As a recording medium, not only a CD-ROM but also a tape or the like can be used.

[0197]

As described above, according to the present invention, a moving image is divided into a background and a foreground, the background is transmitted by dropping frames, and a plurality of foregrounds are transmitted using the transmission area vacated by dropping frames. Can be transmitted. For this reason, a plurality of foreground images can be transmitted without increasing the data compression ratio, so that deterioration in image quality can be reduced.

Since a plurality of foreground images can be prepared in this way, for example, when the present invention is used for a game image, when a certain foreground image is an enemy aircraft image, for example, By setting another foreground image as the explosion pattern, when the enemy aircraft is shot down in the game, the foreground image can be immediately switched to the explosion pattern, and a game with excellent interactivity is performed. It becomes possible.

Also, since both the background and foreground images can be animated, a dynamic image having a sense of depth can be obtained. For example, when the present invention is used in a game machine or the like, a more varied image can be obtained. A certain game can be realized.

[Brief description of the drawings]

FIG. 1 is a part of a functional block diagram for explaining a method of encoding data of a background and foreground image recorded on a recording medium according to the present invention.

FIG. 2 is a part of a functional block diagram for explaining a method of encoding data of a background and foreground image recorded on a recording medium according to the present invention.

FIG. 3 is a diagram for explaining an example of background and foreground images recorded on a recording medium according to the present invention.

FIG. 4 is a diagram for explaining an example of background and foreground images recorded on a recording medium according to the present invention.

FIG. 5 is a diagram for explaining a method for encoding image data of a foreground image recorded on a recording medium according to the present invention.

FIG. 6 is a diagram for explaining data of a foreground image on a recording medium according to the present invention.

FIG. 7 is a diagram showing an example of a recording format of image data recorded on a recording medium according to the present invention.

FIG. 8 is a diagram for explaining a composite screen of a background and a foreground in the image reproducing apparatus according to the present invention.

FIG. 9 is a partial block diagram of an example of an encoding apparatus that implements an embodiment of a method for compressing image data recorded on a recording medium according to the present invention.

FIG. 10 is a block diagram of the rest of an example of an encoding device that implements an embodiment of a method for compressing image data recorded on a recording medium according to the present invention.

FIG. 11 is a diagram for explaining an example of a method of dividing image data according to an embodiment of the image data compression method of the example of FIGS. 9 and 10;

FIG. 12 is a diagram for explaining a table used in an embodiment of the image data compression method in the examples of FIGS. 9 and 10;

FIG. 13 is a diagram for explaining an example of compressed data according to an embodiment of the image data compression method in the example of FIGS. 9 and 10;

FIG. 14 is a diagram for explaining an embodiment of the image data compression method in the examples of FIGS. 9 and 10;

FIG. 15 is a diagram for explaining an example of a table used in an embodiment of the image data compression method in the examples of FIGS. 9 and 10;

FIG. 16 is a diagram for explaining an example of recorded compressed image data in the examples of FIGS. 9 and 10;

FIG. 17 is a diagram showing an example of a format of data recorded on a recording medium according to the present invention.

FIG. 18 shows a sector format of a CD-ROM and identification information I for each sector recorded on a recording medium according to the present invention.
It is a figure for explaining D.

FIG. 19 shows a CD-ROM as an example of a recording medium according to the present invention.
FIG. 3 is a diagram for explaining an example of reproduction data from a ROM.

FIG. 20 is a block diagram of an embodiment of a decoding device as an example of an image reproducing device according to the present invention.

FIG. 21 is a diagram illustrating a divided storage area of a memory.

FIG. 22 is a diagram for explaining a screen that needs to have interactivity;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Game machine main body 5 CD-ROM 6 Program cartridge 8 CRT display 11 CPU 12 DMA controller 13 RAM 14 PPU (Picture Processing Unit) 15 Video RAM 22 Character dividing means 24 First-stage vector quantization means 25 Pallet dividing means 27 Vector quantization means of second stage 38 Recording processing means 41 CD-ROM player 50 General-purpose DSP 101 Original image 102 Background image 103 Foreground image cutout means 104 Character cutout means 105 Foreground image reference data generation means 201a, 201b, 201c Data compression means 202a, 202b, 202c Sorting and coordinate table generation means 204 Path table generation means 205 Print data generation means

Continued on the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) H04N 5/76-5/956 G11B 20/10-20/12 H04N ^7/ 24-7/68

Claims (8)

(57) [Claims] 1. Image data of a moving image comprising a foreground and a background
Is transmitted in a frame unit consisting of a plurality of predetermined sectors.
Transmission method, wherein one of the foregrounds assigned as a background is
The image data representing the background is divided into a plurality of frames, and the image data representing the divided background, and the background
Images representing multiple types of foregrounds that should be selectively superimposed
Image data is transmitted in units of the plurality of frames.
A method for transmitting image data, comprising: 2. The image data transmission method according to claim 1,
Oite, the background image data, which is a still image
Data transmission method. 3. An image data representing a background, and
Image data representing multiple types of foreground selectively displayed in
Data consists of a plurality of predetermined sectors.
Number of frames that are sequentially recorded to form a moving image.
The background is an image data representing the background for one screen.
Image in which the data is divided into a plurality of frames and recorded.
Reading the image data from the recording medium on which the data is recorded
An image reproducing apparatus having a function to play out the foreground of the plurality of types, the foreground to be displayed in accordance with an instruction
Means for selecting image data, means for reading image data from the recording medium, and writing the read image data to a buffer memory.
First writing means; and a plurality of frames from the buffer memory divided into the plurality of frames.
Image data corresponding to the background
While writing to the memory area,
Image data corresponding to the foreground selected from the second image
Second writing means for writing to the memory area; and a plurality of frames for the plurality of frames from the first image memory area.
The divided image data representing the background is divided into a plurality of frames.
Read from the memory area for the second image.
Displays the foreground to be displayed overlapping the image data representing the background.
Read out the image data, combine them and display
Display means for displaying the image on a ray, wherein the display means writes in the first image memory area.
Background obtained from embedded image data for multiple frames
The foreground recorded in the frames
By superimposing them sequentially on the display.
Projecting an image, wherein the second writing means is projecting by the display means
If another foreground is selected by the selecting means,
If selected, a new selection is made from the buffer memory when selected.
Image data corresponding to the extracted foreground is stored in a second image memory.
An image reproducing apparatus for writing in an area. 4. An image reproducing apparatus according to claim 3, wherein
Te, image reproduction instrumentation, wherein the background is a still picture
Place. 5. An image data representing a background, and
Image data representing multiple types of foreground selectively displayed in
Data (including multiple predetermined sectors)
A moving image is recorded sequentially in frame units,
As for the background, image data representing the background for one screen is
Image data that is divided into multiple frames and recorded
Reads and plays back the image data from the recorded recording medium
A foreground to be displayed in accordance with an instruction from among the plurality of types of foregrounds.
Is selected, and when the storage medium is mounted, the image data is read from the storage medium.
And writes the read image data into the buffer memory.
Seen, divided from the buffer memory to the plurality of frames
Image data corresponding to the background
While writing to the memory area,
Image data corresponding to the foreground selected from the second image
Write to the memory area and divide it from the first image memory area into a plurality of frames.
Reading image data representing the divided background for multiple frames
And generating a background, the second image memory
Multiple foregrounds that should be displayed over the background from the area are displayed.
Image data is sequentially read out, and the
Multiple foregrounds recorded in several frames are sequentially superimposed
Video on the display
While the moving image is being projected, another foreground by the selecting means
If is selected, the buffer memory will be
Image data corresponding to the newly selected foreground from the second
Write to the image memory area of
That to the movies out possible to display the image on Display Lee
Characteristic image reproduction method. 6. An image reproducing method according to claim 5, wherein
Te, image reproduction direction, characterized in that the background is a still picture
Law. 7. An image data representing a background, and
Image data representing multiple types of foreground selectively displayed in
Data consists of a plurality of predetermined sectors.
Number of frames that are sequentially recorded to form a moving image.
The background is an image data representing the background for one screen.
Image in which the data is divided into a plurality of frames and recorded.
Reading the image data from the recording medium on which the data is recorded
An image reproducing apparatus having a function to play out the foreground of the plurality of types, the foreground to be displayed in accordance with an instruction
Means for selecting image data, and, when a recording medium is mounted, image data from the recording medium.
Means for reading the image data and writing the read image data into a buffer memory.
A first writing unit, and the plurality of frames are divided from the buffer memory into a plurality of frames.
Image data corresponding to the background
While writing to the memory area,
Image data corresponding to the foreground selected from the second image
Second writing means for writing to the memory area; and a plurality of frames for the plurality of frames from the first image memory area.
The divided image data representing the background is divided into a plurality of frames.
Read from the memory area for the second image.
Displays the foreground to be displayed overlapping the image data representing the background.
Read out the image data, combine them and display
Display means for displaying on a ray, wherein the display means writes in the first image memory area.
Background obtained from embedded image data for multiple frames
In addition, a plurality of foregrounds recorded in the frames
By superimposing them sequentially on the display.
Projecting an image, wherein the second writing means is projecting by the display means
When another foreground is selected by the selecting means,
If it is selected, it is newly selected from the buffer memory
Image data corresponding to the extracted foreground is stored in a second image memory.
An image reproducing apparatus for writing in an area. 8. An image reproducing apparatus according to claim 7, wherein
Te, image reproduction instrumentation, wherein the background is a still picture
Place.