DE29923226U1 - System for storing and playing back compressed image data - Google Patents

Description

Method and system for storage and playback
compressed image data

REFERENCE TO RELATED APPLICATIONS

The entire disclosures of both Japanese Application Nos. Hei 10-122349 filed on May 1, 1998 and Hei 10-169912 filed on June 17, 1998, including specification, claims, drawings and abstract, are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. FIELD OF THE INVENTION

This invention relates to a storage/reproduction system for compressed image data provided by a compressed image data providing device.

2. DESCRIPTION OF THE STATE OF THE ART

A system as shown in Fig. 4 is known as a system for storing image data provided to a computer by a digital video (hereinafter referred to as DV) camera.

In the system, DV data output from the DV camera 38 is provided to a peripheral component interconnect (hereinafter referred to as PCI) bridge 66b through an IEEE 1394 interface 66a. The DV data thus provided is temporarily stored in a memory 27 under the control of the PCI bridge 66b. The DV data stored in the memory 27 is decoded (decompressed) and transmitted to a graphics card 34 under the control of a CPU 23. The graphics card 34 outputs analog RGB signals according to

or in accordance with the decoded data to a cathode ray tube (hereinafter referred to as CRT) 32. In this way, images are displayed on the CRT 32 in accordance with the DV data thus output. At this time, the DV data is stored in a hard disk 26 in accordance with a retrieval initiation command while the DV data is temporarily stored in the memory 27 in parallel with data transfer to the graphics card 34 under the control of the CPU 23. The DV data provided from the DV camera 38 can be stored while being displayed on the CRT 32 by video overlay.

However, the system described above must solve the following problems. In order to display the DV data on the CRT 32 by video superimposition, the DV data decoding must be carried out under real-time conditions. All frames cannot be processed by the CPU 23 if it has lower processing capabilities as it should be. As a result, part of the frames may be missing and/or other problems may occur as a result of the low processing capabilities.

Hardware designed to decode DV data, such as a DV compressor/decompressor (hereinafter referred to as DV CODEC), is required to solve the problems described above.

The problems arise not only in the DV data storage, but also in the playback of the DV data stored on the hard disk 26 when the DV data is read out therefrom.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a data storage system capable of displaying image data by video overlay while storing the data without causing frame loss and/or other difficulty(s),

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even if a computer with a lower processing capability and a simple structure is used in the system.

Another object of the present invention is to provide a data reproduction system capable of reproducing images without frame loss(s) even when a computer having a lower processing capability and a simple structure is used in the system.

Another object of the present invention is to provide a card or method used for these systems.

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A picture storage/playback system capable of switching between a storage mode and a playback mode, wherein in the storage mode compressed picture data is stored while pictures are displayed on a screen, and wherein in the playback mode the stored compressed data is played back, the system comprising:

A) a device for compressed image data having the ability

to switch between a first operating mode and a second operating mode, wherein the device performs the following steps in each operating mode;

al) in the first operating mode^gM the device the compressed

Image data output during the output of analog video signals corresponding to the compressed image data provided thereby in the first mode of operation, wherein the analog video signals are converted from uncompressed digital signals, and wherein the uncompressed digital signals are decompressed from the compressed image data^,

a2) in the second operating mode, the device has the capability of inputting compressed image data from outside into this - e len- ie iiiie

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The present invention is defined in the independent claims. The dependent claims define preferred embodiments of the present invention.

In the following detailed description, the present invention is described in detail using a number of exemplary embodiments. If reference is made to a method in the following description, this relates to a method that can be carried out using a device according to the present invention.

Any method described in this context serves to explain and clarify the device according to the present invention.

Image data that was decompressed from the input compressed image data provided by it and

B) a computer system comprising:

(b1) a device for storing compressed image data, if the compressed image data is made available to it,

b2) a device for displaying the image data made available to it,

b3) a device for converting analog video signals into digital data, the converter device being connected to the device, and

b4) a control device connected to the device for carrying out the following steps:

b41) providing compressed image data received from the device to the storage device, while providing digital data converted by the converter device to the display device while the device is switched to the first operating mode, and

b42) supplying compressed image data stored in the storage device to the device while the device is switched to the second operating mode, and supplying digital data to the display device if analog video signals decompressed by the device are output therefrom, the digital data being converted from the uncompressed analog video signals by the converter device.

Also according to the present invention there is provided a data storage system capable of storing compressed image data while displaying images according to the compressed image data on a display screen, the system comprising:

A) a compressed image data device for outputting compressed image data while outputting analog video signals corresponding to the compressed image data therefrom, and

B) a computer system comprising:

(b1) a device for storing compressed image data, if the compressed image data is made available to it,

b2) a device for displaying the image data according to the digital data provided to it,

b3) means for converting analogue video signals provided by the device into digital data and

b4) a control device connected to the device and the converter device, the control device carrying out the following step:

b41) providing digital data converted by the converter device to the display device, while providing compressed image data output from the device to the storage device.

Further according to the present invention there is provided a data storage system capable of storing compressed image data while displaying images according to the compressed image data on a monitor, the system comprising:

A) a compressed image data device which outputs analog video signals when compressed image data is output therefrom, the analog video signals corresponding to the compressed image data,

B) having a computer:

b1) a memory that temporarily stores compressed image data provided to it,

(b2) a central processing unit which carries out the control of storing the compressed image data on a hard disk while storing the compressed image data in the memory,

b3) a monitor for the computer that displays image data provided to it, and
b4) a graphics card that controls the monitor display, and

C) having a display/memory overlay card:

c1) a video decoder that converts analog video signals into digital data, the analog video signals being provided by the device,

c2) a compressed image data interface that receives compressed image data provided by the device, the compressed image data interface being connected to the device,

c3) a display/memory controller associated with the display card portion

provides digital data output by the video decoder while storing compressed image data into memory via the interface, wherein the display/storage controller is connected to the video decoder and the compressed image data interface.

Still further according to the present invention there is provided a display/memory overlay card comprising:

a compressed image data interface connected to a compressed image data device, the interface receiving compressed image data provided by the device,

a video decoder that converts analog video signals into digital data, the analog video signals being output from the device, the analog video signals corresponding to the compressed image data, and

a display/memory controller that is connected to the video decoder, the

interface and a graphics card, wherein the controller supplies digital data output from the video decoder to the graphics card via a bus line, while compressed image data is stored in a memory of the computer through the interface via the bus line.

According to the present invention there is provided: a display

/Memory overlay card having the capability of storing compressed image data from a compressed image data device while displaying images according to the compressed image data on a screen of a computer system, and having the capability of reproducing the stored data,

wherein the card is connected to the device capable of switching between a first operating mode and a second operating mode, the device performing the following steps in each of the operating modes:

al) in the first operating mode, the device outputs the compressed image data while outputting analog video signals corresponding to the compressed image data,

a2) in the second operating mode, the device outputs analog video signals, the signals corresponding to compressed image data input from the outside,
where the card has:

a video decoder for converting analog video signals into digital data, the analog video signals being provided by the device,

a compressed image data interface for receiving and transmitting the compressed image data between the device, the interface being connected to the device and

a display/memory controller coupled to the device, the controller performing the following steps:

b1) Supply of digital data converted by the video decoder

to a graphics card which controls a display of a monitor of the computer system via a bus line, while compressed image data received through the interface are stored in a memory of the computer system in a display/memory overlay mode, and b2) outputting the digital

Data via the bus line to the graphics card, while compressed image data stored on a hard disk of the computer system is provided to the device via the interface in a playback/display mode.

Also provided according to the present invention: a

Data storage/reproduction method for storing/reproducing compressed image data provided by a compressed image data device, the device being capable of switching between a first operating mode

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and a second operating mode, wherein the device performs the following steps in each of the operating modes;

al) in the first mode of operation, the device outputs compressed image data while outputting analog video signals converted from uncompressed image data decompressed from the compressed image data,

a2) in the second operating mode, the device outputs analog video signals converted from uncompressed image data decompressed from externally input compressed image data, the method comprising the steps of:

storing the compressed image data provided by the device on a data storage medium while displaying images according to the analog video signals provided by the device during a data storage mode if the device is in the first operating mode, and

providing compressed image data stored on the data storage medium to the device; and displaying images corresponding to the analog video signals provided by the device in a data playback mode on a screen if the device is in the second mode of operation.

Further, according to the present invention, there is provided a data storage method for storing compressed image data provided by a compressed image data device on a data storage medium of a computer system while displaying images according to the compressed image data on a screen of the computer system, the method comprising the steps of:

Connecting the device that has a connection for compressed

Image data and an analog video signal port, with the computer system, wherein the device outputs compressed image data via the data port, and outputs analog video signals via the signal port, wherein the analog signals consist of uncompressed digital image data

which are decompressed from the compressed image data output from the data port, and

Storage of the compressed data provided by the device

Image data on the storage medium of the computer system without decompressing it, while displaying images on the screen of the computer system according to the analog video signals provided by the device.

Furthermore, according to the present invention, there is provided:

a data reproduction method for reproducing images according to compressed image data stored on a data storage medium of a computer system on a screen of the computer system, the method comprising the steps of:

Connecting a device for compressed image data to the computer system, the device carrying out a decompression of compressed image data and a conversion of the decompressed image data into analog signals,

Delivering compressed image data stored on the data storage medium to the device and

Displaying images according to the analog signals received by the device, the analog signals decompressed by the device, on the screen.

While the novel features of the invention are set forth in a general manner as to organization and content, the same will be better understood and appreciated from the following detailed description taken in conjunction with the drawings, together with other objects and features thereof.

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BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a functional block diagram of a data storage/reproduction system 1 according to the present invention.

Figure 2 is a block diagram showing an example of a hardware structure of the data storage-reproduction system 1 according to the present invention.

Figure 3 is another block diagram showing the details of a DV camera and a display/memory overlay card.

Figure 4 is another block diagram illustrating the hardware structure of a conventional data storage/playback system.

BEST MODE FOR CARRYING OUT THE PRESENT INVENTION

1. FUNCTIONAL BLOCK DIAGRAM

An embodiment of the present invention will hereby be described with reference to the drawings. Figure 1 is a functional block diagram of a data storage/reproduction system 1. A data storage/reproduction system 1 is a system having the capability of storing image data therein while displaying images according to image data provided from a compressed image data device on a display of a computer system, the system 1 also having the capability of reproducing the image data thus stored.

The device 3 can be switched to either a first operating mode or a second operating mode. In the first operating mode, the device 3 outputs both the compressed image data and the analog

Video signals corresponding to the compressed image data. Compressed image data can be input to the device 3 from outside, and analog video signals decompressed and converted by the device 3 are output therefrom in a second operating mode.

Furthermore, the computer system 20 has a storage device 13, a display device 15, a converter device 12 and a control device 14.

The storage device 13 stores compressed image data when image data is provided to it. Likewise, the display device 15 displays images provided to it. Furthermore, the converter device 12, which is connected to the device 3, converts the analog video signals into digital data.

The image data converted by the converter device 12 is made available to the display device 15, while the compressed image data provided by the device 3 is stored in the storage device 13 under the control of the control device 14 if the device 3 is in the first operating mode, wherein the converter device 12 converts analog video signals provided by the device 3 into the image data.

Furthermore, if the device 3 is in the second operation mode, the compressed image data stored in the storage device 13 is provided to the device 3, and the analog video signals output by the device 3 are converted into digital data by the converter device 12 and provided to the display device 15 under the control of the control device 14.

2. HARDWARE STRUCTURE

Figure 2 shows an example of a hardware structure of System 1. The

System 1 includes a DV camera 38, a computer 21, and a CRT 32. In this embodiment, the DV camera 38 constitutes a compressed image data device, the computer 21 and the CRT 32 together constitute the computer system, and the DV data constitutes the compressed image data.

Details of the DV camera 38 will be described herewith with reference to Figure 3. The DV camera 38 includes an image data processor 55, a DV CODEC 53, an IEEE 1394 interface (hereinafter referred to as interface) 51, a controller 54, a mode selector 56, a DV data output terminal 57, a video encoder 58 and an analog video signal output terminal 59. Other mechanisms with which available DV cameras are equipped, such as drive mechanisms, optical systems and liquid crystal displays (hereinafter referred to as LCD), have been omitted from the drawing for clarity.

The data processor 55 converts the image data provided to it into YUV digital signals. The DV CODEC 53 compresses the YUV digital signals into digital form when the YUV digital signals are provided to it. The compressed digital data is recorded on a video tape 52 while being provided to the interface 51 for output via the output terminal 57. Furthermore, the DV CODEC 53 converts DV data into YUV digital data and provides it to the video encoder 58 if the DV data is available. The encoder 58 converts the YUV digital signals provided by either the data processor 55 or the DV CODEC 53 into analog video signals and outputs the analog video signals via the output terminal 59.

The mode selector switch 56 is used to change the operating modes of the DV camera 38 to either an image capture mode or a playback mode. In the image capture mode, the controller 54 connects the data processor 55 to the DV CODEC 53 so as to provide the YUV digital signals output from the data processor 55 to the DV CODEC 53. In this way, the image data provided by the data processor 55 is compressed by the DV CODEC 53 on a frame by frame basis and the compressed signals are recorded on the video tape 52, while the compressed signals are output from the output terminal 57 via the interface 51. Furthermore, the YUV digital signals provided by the data processor 55 are converted into analog video signals by the encoder 58, and the analog signals thus converted are output via the output terminal 59.

In the playback mode, the controller 54 provides the DV data recorded on the tape 52 to the interface 51. In response, the DV data recorded on the tape 52 is output through the output terminal 57. Further, the DV data recorded on the tape 52 is provided to the DV CODEC 53 under the control of the controller 54. The DV data thus provided is decompressed by the DV CODEC 53 and output to the encoder 58. The encoder 58 converts the decompressed data into analog video signals, and provides the analog video signals to both an LCD (not shown) and the output terminal 59. Then, the DV data recorded on the tape 52 is displayed on the LCD, while the analog video signals are output through the output terminal 59.

In this embodiment, both the image capture mode and the playback mode for reproducing the data recorded on the tape constitute the first operation mode.

Further, the controller 54 provides DV data inputted by an external device or the like to the DV CODEC 53 when no output of the tape is detected and when DV data inputted by the external device is detected through the output terminal 57 and the interface 51. The DV data thus provided is decompressed by the DV CODEC 53. The data thus decompressed is converted into analog video signals by the encoder 58. Then, images of the DV data inputted by the external device are displayed on the LCD while the analog video signals are outputted through the output terminal 59.

In this embodiment, the playback mode for playing the DV data input from the external device is the second operation mode.

Details of the computer 21 will be described with reference to Figure 2. The computer 21 includes a playback/storage interface card 36, a hard disk 26, a keyboard 28, a memory 27, a CPU 23, a flexible disk drive (hereinafter referred to as FDD) 25, a graphics card 34 and a bus line 29.

The CPU 23 controls other parts via the bus line 29 according to a control program stored on the hard disk 26.

The control program is a program installed on the hard disk 26 by reading a floppy disk 25a through the FDD 25. The control program can also be installed on the hard disk 26 from computer-readable media with program(s) such as CD-ROMs, IC cards or the like, other than FDDs. Furthermore, the control program can be downloaded to the hard disk 26 through a communication line.

In this embodiment, the control program stored on the diskette(s) is indirectly executed on the computer by installing the control program on the hard disk 26 via diskette(s). But the

The control program is not limited to this, but may be directly executed on the computer system via the FDD 25. The control program that can be executed by the computer used in this embodiment is not only the program itself that can be directly executed by installation on the computer as it is, but the control program of the embodiment described here also includes computer programs that need to be converted into other forms such as uncompressed data, etc., as well as other control programs that are executed on the computer by combining with other modules such as operating systems or libraries.

The DV data provided by the DV camera 38 is also stored in the hard disk 26. Various calculation results as well as the DV data are stored in the memory 27. Furthermore, the CRT 32 is connected to the graphics card 34.

Details of the card 36 will be described herewith with reference to Figure 3. The card 36 includes an IEEE 1394 interface (hereinafter referred to as interface) 41, a video decoder 42, a PCI bridge 43, a DV data input port 47, and an analog video signal input port 49. The video decoder 42 is connected to the input port 49. And the interface 41 is connected to the input port 47. Furthermore, the video decoder 42 converts the analog video signals provided through the input port 49 into digital data and provides the digital data to the PCI bridge 43. The DV data output to the input port 47 is provided to the PCI bridge 43 under control of the interface 41. The PCI bridge 43 outputs the digital data provided by the decoder 42 to the graphics card 34 shown in Figure 2. In addition, the PCI bridge 43 outputs the DV data provided by the interface 41 to the memory 27 of Figure 2 in accordance with a start and a stop command for retrieving the DV data, both provided by the CPU 23 of Figure 2.

Detailed command procedures will be described later. In other words, the card 36 can perform direct memory access (DMA) without using the CPU 23, so that no DV CODEC needs to be mounted thereon.

3.FADE-IN PLAYBACK METHODS

Next, methods of video superimposition storage/reproduction e-def-- will be described. Methods of video storage in which image data recorded on the tape 52 installed in the video camera 38 is displayed on the CRT 32 in a superimposition manner while storing a desired part of the data on the hard disk will be described here as an example.

An operator of the system connects the DV camera 38 and the card 36 so as to exchange data between them. In practice, the operator connects the output terminals 57, 59 and the input terminals 47, 49, respectively, as shown in Fig. 2. Both the DV data terminal 47 and the terminal 57 form an image data terminal for compressed image data in this embodiment.

The operator (user) enters a video capturing initialization command via the keyboard 28. Upon receipt of the command, the CPU 23 initializes the card 36.

Playback of data recorded on the tape 53 is performed by the operator's operations such as loading the tape 52 into the DV camera 38 and performing the necessary steps for the playback mode. The DV CODEC 53 of Fig. 3 decompresses DV data supplied from the tape 52, and the thus decompressed data is converted into analog signals by the video encoder, and the analog signals are output through the output terminal 59. The thus output

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analog signals are supplied to the video decoder 42 through the input terminal 49. The analog signals supplied to the video decoder 42 are thereby converted into digital signals, and the converted signals are output to the PCI bridge 43. The PCI bridge 43 outputs the digital signals to the graphics card 34 via a bus line (a PCI bus line). In this way, the video images recorded on the tape 52 in the DV camera 38 are displayed on the CRT 32 as moving images.

The operator who watches the moving pictures displayed on the CRT inputs the initiation command of the DV data from the keyboard when a desired picture is displayed on the CRT. Upon input of the initiation command, the CPU 23 supplies it to the PCI bridge 43 shown in Fig. 3.

Incidentally, the original DV data of the moving pictures displayed on the CRT 32 are supplied to the PCI bridge 43 via the DV CODEC 53 of the DV camera 38, the interface 51, the connector 57, the DV data connector 47 of the card 36 and the interface 41.

The DV data supplied through the interface 41 is transferred to the memory 27 of Fig. 2 when the PCI bridge receives the initiation command. The CPU 23 transfers the DV data stored in the memory 27 to the hard disk 26 when the transfer of the DV data is detected.

The operator, who is observing the moving images displayed on the CRT, inputs a DV data retrieval termination command from the keyboard 28 when the retrieval of the desired images is completed. Upon input of the termination command, the CPU 23 supplies the termination command to the PCI bridge 43 of Fig. 3. The PCI bridge 43 terminates the transfer of the DV data to the memory 27.

During data storage in the memory 27, continuously moving pictures are displayed on the CRT 32 because the PCI bridge 43 outputs both the data from the interface 41 and that from the video decoder 42 in a manner such that they do not collide with each other.

The following procedures are carried out in the system according to the present invention. The DV camera 38 outputs DV data recorded on the tape 53 and reproduced thereby to the PCI bridge through the terminal 57, while outputting analog video signals decoded and converted from the DV data to the output terminal 59. The video decoder 42 converts the analog signals thus output into digital signals. The PCI bridge 43 outputs the DV data received from the DV camera 38 to the graphics card 34. In this way, the video images output from the DV camera are displayed on the CRT 32. Also, the PCI bridge 43 transfers the DV data supplied through the interface 41 to the memory 27. The data stored in the memory 27 is written to the hard disk 26 under the control of the CPU 23. The DV data recorded on the tape 52 in the DV camera 38 can be displayed on the monitor of the computer system while storing a desired part of the moving images in the storage medium of the computer by executing these procedures.

Images for monitoring (displaying) and storage are output through the analog video signal terminal and the DV data output terminal, respectively. The following advantages can be achieved by the separate output.

One of the advantages is that entered DV data can be stored in a

hard disk while being monitored (displayed) as moving images that move smoothly without missing frames without the need for additional hardware such as a DV data decompression card. Another advantage is that no decoding by the CPU

using a program, so that the CPU load can be reduced. Specifically, the PCI bridge 43 transfers DV data to the memory 27 using a bus mastering technique without using the CPU 23 in the above-mentioned embodiments. In this way, the CPU load can be further reduced. Another advantage is that the DV CODEC, an expensive component, is not required in the system because the hardware in the DV camera is used as a substitute for it. As a result, the entire system can be manufactured at a low manufacturing cost.

The interface 41 and the decoder 42, both of which supply data to the PCI bridge 43, are mounted on the card 36, and the PCI bridge 43 outputs both the data from the interface 41 and the video decoder 42 so that they do not collide with each other. In this way, additional free space can be expected in the PCI slots, compared to when both the interface 41 and the video decoder 42 are mounted separately on the card 36.

A further advantage is that no driver is required to control the video decoder in the system, compared to when the video decoder 42 is mounted on the graphics card 34.

Playback of the DV data stored in the hard disk is carried out as follows in the system described above. The operator switches the mode selector switch 56 of the DV camera 38 to the playback mode and inputs a playback command through the keyboard 28.

Upon receipt of the command, CPU 23 delivers it to the PCI bridge

43. Furthermore, the CPU 23 reads the DV data from the hard disk 26 and transmits it to the memory 27. The PCI bridge 43 reads the DV data from the memory 27 and transmits it to the DV camera 38 via the interface 41. The DV CODEC 53 decodes and converts the DV data thus transmitted into analog

signals, and the analog signals are output therefrom via the output terminal 59. The video decoder 42 converts the analog video signals into digital data and supplies them to the PCI bridge 43. The PCI bridge 43 transfers the digital data directly to a frame memory in the graphics card 34. In this way, the DV data stored in the hard disk 26 can be displayed on the CRT.

The PCI bridge 43 controls the timing between the data reading of the

DV data from the memory and data transfer of the DV data received from the video decoder 42 on a time sharing basis in such a way that both of the processes appear to be performed simultaneously.

4. OTHER EXAMPLES OF IMPLEMENTATION
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Although in the previous embodiments the DV data recorded on the tape 52 is stored in the hard disk 26 while the data is displayed on the CRT 32 in a video superimposed manner, in the embodiments, similar procedures can be carried out even when the DV camera 38 is in the image capture mode since both DV data and analog video signals are output from the camera 38.

Although in the previous embodiments, a part of the DV data supplied by the DV camera 38 is stored in the hard disk 26 by inputting either an initiation command or the termination command, the entire DV data supplied by the DV camera 38 may be stored in the hard disk 26. In this case, the operator can set the computer system to a state capable of performing video recording while supplying desired moving images from the DV camera 38.

Although in the previous embodiments both the initiation command and the termination command were input through the keyboard, these commands may also be input through other input devices such as a mouse or the like.

In the previous embodiments, a digital overlay technique is used in which the video decoder 43 converts the analog video signals supplied by the DV camera 38 into a data format capable of being processed by the graphics card 34, and the PCI bridge 43 transmits the converted data to the graphics card. Alternatively, instead of the digital overlay technique, an analog overlay technique may be used in which signals output from both the graphics card and an additional frame memory are synthesized with an analog circuit and output to the monitor, with the display rate of the frame memory matching that of the graphics card.

In the embodiment described above, the data processor 55 converts the image data into YUV digital signals. The data processor may convert the image data into other formats of digital signals, such as RGB digital signals.

DV data is used as compressed image data in the foregoing embodiment, and the compressed image data includes a concept representing that the entire data should be compressed once and decompressed when displayed. For example, the data to be processed in the Moving Picture Experts Group (hereinafter referred to as MPEG) or the Joint Photographic Experts Group (hereinafter referred to as JPEG) can be used as the data to be transformed with discrete cosine transform (hereinafter referred to as DCT). The data compressed by other methods such as wavelet transform or vector quantization can also be used as compressed image data. Furthermore, data transformation methods using the

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Capable of reversibility can be used as well as data transformations that are not capable of reversibility.

The DV camera used as a DV imaging device and capable of recording images is used as a compressed image data device. Other devices such as a computer having a DV card or DV deck installed can also be used as a compressed image data device.

Although the compressed image data supplied from the compressed image data apparatus is stored in a magnetic storage medium such as the hard disk in the previous embodiment, the compressed image data may be stored in other types of data storage media such as an optical data storage medium or an electrical data storage medium. The compressed image data may also be stored in data storage media such as a storage medium defined by a ZIP format, a compact disc-recordable (CDR), a mini disk (MD), a phase-change dual-disc (PD-disc), a digital video disc-access memory (DVD-RAM), a ferroelectric memory, and the like.

Both a computer software and the CPU 23 are used to

Realization of the functions shown in Fig. 1 in the above embodiments, however, part or all of the functions may be realized by computer hardware such as logic circuits or the like.

In a data storage/reproduction system according to the

present invention, the apparatus performs the following steps in each of the operating modes; in the first operating mode, the apparatus outputs the compressed image data which is output while analog video signals corresponding to the compressed image data are output from this

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wherein the analog video signals are converted from uncompressed digital signals, and the uncompressed digital signals are decompressed from the compressed image data, and wherein in the second mode of operation the device is capable of receiving compressed image data as input from the outside and outputting analog video signals converted from uncompressed digital image data which are decompressed from the input compressed image data supplied thereby. The control device connected to the device performs the steps of supplying compressed image data received from the device to the storage device while supplying digital data converted by the conversion device to the display device when the device is switched to the first operation mode, and supplying compressed image data stored in the storage device to the device when the device is switched to the second operation mode, and supplying digital data to the display device when analog video signals decompressed by the device are outputted therefrom, the digital data being converted from the decompressed analog video signals by the conversion device. In this way, both data storage with visual confirmation of the input images and data reproduction can be carried out by the system with a simple structure.

In a data storage system according to the present invention, a control device is connected to a compressed image data device and a converting device, and the control device performs a step of supplying digital data converted by the converting device to a display device while supplying compressed image data output from the compressed image data device to a storage device. In this way, data storage with visual confirmation of the input images can be carried out by a system having a simple structure.

In a data storage system according to the present invention, a compressed image data device outputs analog video signals corresponding to compressed image data when compressed image data is output therefrom. The compressed image data supplied from the compressed image data device is received by a compressed image data interface included in a display/storage overlay card. The compressed image data thus received is temporarily stored under the control of a display/storage controller. The compressed image data stored in the memory is stored in a hard disk under the control of a central processing unit. On the other hand, a video decoder converts the analog signals supplied from the compressed image data device into digital data. Also, the display/storage controller supplies the digital data output by the video decoder to a display card part. Further, the display card part controls the display of the digital data on a monitor of a computer. In this way, the system with a simple structure can perform data storage with visual confirmation of the entered data.

In a display/storage overlay card according to the present invention, a video decoder converts analog video signals into digital data, the analog video signals corresponding to compressed image data output from the compressed image data device which outputs the analog video signals when compressed image data is output therefrom. A display/storage controller connected to the video decoder and a compressed image data interface supply digital data output from the video decoder to a display card portion connected to the monitor via a bus line, while compressed image data is stored in a memory of the computer through the compressed image data interface via the bus line. In this way, data storage with high-speed video overlay can be carried out, as well as reducing the CPU load.

In a display/memory overlay card according to the present invention, in a first operation mode, compressed image data and video signals corresponding thereto are output from a compressed image data device. A display/memory controller supplies digital data converted by a video decoder to a graphics card portion which controls the display of a monitor of a computer system via a bus line, while compressed image data received via a compressed image data interface is stored in the memory of the computer system in a display/memory overlay mode. In this way, data storage on the hard disk with video overlay on the monitor can be carried out by only performing a step for transferring the data stored in the hard disk.

The display/storage controller supplies compressed image data stored in the hard disk of the computer system to the compressed image data device through the compressed image data interface in a playback/display mode. The compressed image data device is capable of receiving compressed image data from the outside as input and outputting analog video signals decompressed and converted by the compressed image data device in a second operation mode. In this way, the analog video signals thus output are supplied to the video decoder. The display/storage controller outputs the digital data converted by the video decoder to the graphics card part through the bus line. Therefore, reproduction of images can be carried out even if no means for decompressing the compressed image data is included in the computer.

In a data storage process e

the image data supplied by the compressed image data device is stored in a data storage medium, while images are generated in accordance with the analog video signals supplied by the device during a data storage mode when the device is in the first mode

·

and when the apparatus is in the second mode, the compressed image data stored in the data storage medium is supplied to the apparatus and images are displayed on a display screen in accordance with the analog video signals supplied from the apparatus during a data reproduction mode. In this way, compressed image data can be stored while the image data is displayed by the compressed image data apparatus without a dedicated card or an image compression device being installed on the computer, since the analog video signals corresponding to the compressed image data are output from the compressed image data apparatus.

In a data storage method -e—etef—li, compressed image data supplied through a compressed image data terminal of a compressed image data device is stored on a data storage medium of a computer system without performing decompression while images are displayed on a display screen of the computer system in accordance with the compressed image data supplied from the compressed image data device. In this way, the compressed image data can be stored while the image data from the compressed image data device is displayed without a special card or device dedicated to image compression being installed on the computer, since the analog video signals corresponding to the compressed image data are output from the compressed image data device.

In a data reproduction method -def-i-, images generated according to compressed image data stored in a data storage medium of a computer system are displayed on a display screen of the computer system, the method comprising the steps of: connecting a compressed image data device to the computer system, the compressed image data device being capable of decompressing compressed data, converting digital signals into

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analog signals and outputting the thus converted analog signals therefrom, supplying the compressed image data stored in the data storage medium to the compressed image data device, and displaying images on the display screen according to the analog signals received from the compressed image data device, the analog signals having been decompressed. In this way, compressed image data can be reproduced without installing a special card or device dedicated to image compression in the computer.

The following are definitions of words and phrases used in the following claims, as well as a correspondence between these words and phrases and words and phrases in the embodiments.

The term "storage device" corresponds to the memory 27 and the hard disk 26 from Fig. 2 in the embodiments described above.

The broader term "converting device" corresponds to the PCI bridge 43 from Fig. 3 in the embodiments described above.

Data transfer performed by the PCI bridge 43 to each of the memory 27, the graphics card 34 and the interface 41, as well as data transfer performed by the CPU 23 to the hard disk 26 from the memory 27, each correspond to the term "control".

Another term "display/memory controller" corresponds to the PCI bridge 43 of Fig. 3 in the embodiments described above.

The further term "display device" corresponds to both the graphics card 34 and the CRT 32 from Fig. 2 in the embodiments described above.

The further term "graphics card part" corresponds to the graphics card 34 from Fig. 2 in the embodiments described above.

The term "compressed image data" means image data that has been compressed, regardless of the method, degree of compression, or other factors.

The terms "decompressed", "decompression" mean a step to perform the decoding of compressed image data, it is also called the expansion of data.

A phrase "analog video signals containing compressed image data

The phrase "correspond to" certainly includes signals that have been decoded from compressed image data and then converted to analog format, and the phrase also includes signals that have been converted to analog format before the compressed image data has been decoded.

While the invention has been described in terms of its preferred embodiments, it is to be understood that the terms used are terms of description rather than limitation and that changes may be made within the appended claims without departing from the true scope and spirit of the invention in its broader aspects.

Claims (22)

1. A data storage/reproduction system capable of switching between a storage mode and a reproduction mode, wherein in the storage mode compressed image data is stored while images are displayed on a screen, and wherein in the reproduction mode the stored compressed data is reproduced, the system comprising: A) a compressed image data device capable of switching between a first operating mode and a second operating mode, the device performing the following steps in each operating mode; 1. in the first operating mode, the device outputs the compressed image data output during the output of analog video signals corresponding to the compressed image data provided thereby in the first operating mode, wherein the analog video signals are converted from uncompressed digital signals, and wherein the uncompressed digital signals are decompressed from the compressed image data, 2. in the second mode of operation, the device has the ability to input compressed image data from outside and to output analog video signals converted from uncompressed digital image data decompressed from the input compressed image data provided by it and B) a computer system comprising: 1. a device for storing compressed image data, if the compressed image data is made available to it, 2. a device for displaying the image data made available to it, 3. a device for converting analog video signals into digital data, the converter device being connected to the device, and 4. a control device connected to the device for carrying out the following steps: 5. providing compressed image data received from the device to the storage device while providing digital data converted by the converter device to the display device while the device is switched to the first operating mode, and 6. supplying compressed image data stored in the storage means to the device while the device is switched to the second operating mode, and supplying digital data to the display device if analog video signals decompressed by the device are output therefrom, the digital data being converted from the uncompressed analog video signals by the converter means. 2. A data storage system capable of storing compressed image data while displaying images on a screen according to the compressed image data, the system comprising: A) a compressed image data device for outputting compressed image data while outputting analog video signals corresponding to the compressed image data therefrom, and B) a computer system comprising: 1. a device for storing compressed image data, if the compressed image data is made available to it, 2. a device for displaying the image data according to the digital data provided to it, 3. means for converting analog video signals provided by the device into digital data and 4. a control device connected to the device and the converter device, the control device carrying out the following step: 5. Providing digital data converted by the converter device to the display device, while providing compressed image data output from the device to the storage device. 3. A data storage system capable of storing compressed image data while displaying images according to the compressed image data on a monitor, the system comprising: A) a compressed image data device which outputs analog video signals when compressed image data is output therefrom, the analog video signals corresponding to the compressed image data, B) having a computer: 1. a memory that temporarily stores compressed image data provided to it, 2. a central processing unit which controls the storage of the compressed image data on a hard disk while the compressed image data is stored in the memory, 3. a monitor for the computer that displays image data provided to it, and 4. a graphics card that controls the monitor display, and C) having a display/memory overlay card: 1. a video decoder that converts analog video signals into digital data, the analog video signals being provided by the device, 2. a compressed image data interface that receives compressed image data provided by the device, the compressed image data interface being connected to the device, 3. a display/storage controller that provides digital data output by the video decoder to the display card portion while storing compressed image data into memory via the interface, the display/storage controller being connected to the video decoder and the compressed image data interface. 4. Display/memory overlay card comprising:
a compressed image data interface connected to a compressed image data device, the interface receiving compressed image data provided by the device,
a video decoder that converts analog video signals into digital data, the analog video signals being output from the device, the analog video signals corresponding to the compressed image data, and
a display/memory controller connected to the video decoder, the interface and a graphics card, the controller supplying digital data output from the video decoder to the graphics card via a bus line, while compressed image data is stored in a memory of the computer by the interface via the bus line. 5. A display/storage overlay card capable of storing compressed image data from a compressed image data device while displaying images according to the compressed image data on a screen of a computer system, and capable of reproducing the stored data, the card being connected to the device capable of switching between a first operating mode and a second operating mode, the device performing the following steps in each of the operating modes: 1. In the first operation mode, the device outputs the compressed image data while outputting analog video signals corresponding to the compressed image data, 2. In the second operating mode, the device outputs analog video signals, the signals corresponding to compressed image data input from the outside,
where the card has:
a video decoder for converting analog video signals into digital data, the analog video signals being provided by the device,
a compressed image data interface for receiving and transmitting the compressed image data between the device, the interface being connected to the device, and
a display/memory controller coupled to the device, the controller performing the following steps: 3. supplying digital data converted by the video decoder to a graphics card that controls a display of a monitor of the computer system via a bus line, while storing compressed image data received through the interface in a memory of the computer system in a display/memory blending mode, and 4. Outputting the digital data provided by the video decoder to the graphics card via the bus line, while providing the device with compressed image data stored on a hard disk of the computer system via the interface in a playback/display mode. 6. A data storage/reproduction system according to claim 1, wherein the compressed image data device is a digital video camera. 7. The data storage system of claim 2, wherein the compressed image data device is a digital video camera. 8. The data storage system of claim 3, wherein the compressed image data device is a digital video camera. 9. A display/storage overlay card according to claim 4, wherein the compressed image data device is a digital video camera. 10. A display/storage overlay card according to claim 5, wherein the compressed image data device is a digital video camera. 11. A data storage/reproduction system according to claim 1, wherein the compressed image data is data compressed by a discrete cosine transform. 12. The data storage system of claim 2, wherein the compressed image data is data compressed by a discrete cosine transform. 13. The data storage system of claim 3, wherein the compressed image data is data compressed by a discrete cosine transform. 14. A display/storage overlay card according to claim 4, wherein the compressed image data is data compressed by a discrete cosine transform. 15. The display/storage overlay card of claim 5, wherein the compressed image data is data compressed by a discrete cosine transform. 16. A display/storage overlay card according to claim 4, wherein the compressed image data interface is an IEEE 1394 interface. 17. The display/memory overlay card of claim 16, wherein the display/memory controller is a PCI bridge. 18. The display/memory overlay card of claim 17, wherein the PCI bridge controls the timing between the data reading of the DV data from the memory and the data transfer of the DV data received from the video decoder on a time sharing basis such that both processes appear to be performed simultaneously. 19. A display/storage overlay card according to claim 17, wherein the compressed image data interface and the video decoder, both of which supply data to the PCI bridge, are mounted on the card and the PCI bridge outputs the data from the interface and that from the video decoder so that they do not collide with each other. 20. A display/memory overlay card according to any one of claims 16 to 19, further comprising:
a DV data input connector; and
an input connector for an analog video signal. 21. A display/memory overlay card according to claim 20, wherein
the compressed image data interface is connected to the DV data input connector; and
the video decoder is connected to the input connector for the analog video signal. 22. A display/memory overlay card according to any one of claims 16 to 21, wherein the card can perform direct memory access (DMA) without a DV CODEC mounted thereon.