JP2002320198A - Video recording device - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To extend the moving image shooting time by enabling switching of the frame rate at the time of moving image shooting and compressing the amount of shooting data during a low frame rate period. An electronic still camera (1) has a moving image photographing function of continuously storing a periodic frame image generated by an image sensor (2) for an arbitrary time in a storage unit (5), and stores the periodic frame image in the storage unit (5). Switching means 4 for switching the frame rate of the frame image to be stored between a high frame rate and a low frame rate, and detecting means 6 for detecting a physical quantity representing a state of a subject in the frame image
And control means 7 for outputting a control signal for instructing the switching means 4 to switch the frame rate to a high frame rate when the physical quantity detected by the detection means 6 meets a predetermined determination condition. Is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a moving picture recording apparatus, and more particularly to a moving picture recording apparatus such as a movie camera capable of photographing and recording a moving picture.

[0002]

2. Description of the Related Art An electronic still camera, such as a digital camera, which is a kind of moving picture recording apparatus, is equipped with a CCD (Charge).
An image signal of an object photographed by an image sensor such as a coupled device is written and stored in a storage medium such as a semiconductor memory, and the immediacy of image confirmation is higher than that of a conventional camera (silver halide camera). However, today, the image sensor further has a frame image generating function (generally, an image signal having a frame rate of about 30 frames per second can be generated). 2. Description of the Related Art Electronic still cameras have become widespread in which not only still images but also moving images can be captured by recording the frame image signal for an arbitrary period of time.

[0003]

However, in general, the capacity (storage capacity) of a storage medium of an electronic still camera is about several megabytes (megabytes) or several tens of megabytes. Since the storage capacity of the dedicated device is far smaller than that of the dedicated device, there is a problem that it is not possible to shoot a moving image of the electronic still camera for a long time.

[0004] Therefore, an object of the present invention is to make it possible to switch the frame rate at the time of shooting a moving image, and to compress the amount of shooting data during a low frame rate period, thereby reducing the time for shooting a moving image. The idea is to extend it.

[0005]

According to the present invention, there is provided a moving image recording apparatus comprising: an acquiring unit for sequentially acquiring a plurality of frame images constituting a moving image; and a frame unit for sequentially acquiring the frame images sequentially acquired by the acquiring unit. Storage control means for storing;
Detecting means for detecting a physical quantity representing a state of a subject in the frame image; and the moving image when storing the frame image in the storage means when the physical quantity detected by the detecting means meets a predetermined determination condition. And control means for changing the frame rate. In the moving image recording apparatus according to the present invention, when the physical quantity representing the state of the subject matches a predetermined determination condition, or when a frame rate change operation by the user is detected,
The frame rate of the moving image when the frame image is stored in the storage unit is changed.

[0006]

Embodiments of the present invention will be described below in detail with reference to the drawings. <First Embodiment> FIG. 1A is a simplified block diagram of an electronic still camera according to a first embodiment. In this figure, the electronic still camera 1 includes an image sensor 2 (acquisition unit), a frame image generation unit 3 (acquisition unit), a frame rate control unit 4 (storage control unit, control unit), a recording unit 5 (storage unit), It comprises a sound level detecting section 6 (detecting means) and a frame rate determining section 7 (control means), and the functions of these sections are as follows.

[0007] First, the image sensor 2 generates a frame image signal of a subject 9 captured via an optical system 8 such as a photographic lens. This image sensor 2 is a CCD
Type and CMOS (Complementary Me)
This is a two-dimensional image sensor of a tal-oxide semiconductor type or another type, which repeatedly generates and outputs a still image signal of the subject 9 at a predetermined cycle (frame rate).

For example, NTSC (National TV Standard) often used for electronic still cameras
ds Committee) image sensor
A still image signal of approximately 30 frames per second (accurately, 29.97 frames; hereinafter rounded down to 30 frames for convenience) is generated and output. In this case, the above “period” is about 1/30 second.

The illustrated image sensor 2 is not particularly limited, but is assumed to be a color image sensor having a color filter mounted on a light receiving surface. Although not shown in the drawing, a sample-and-hold circuit and an analog-to-digital conversion circuit are connected to the output terminal,
It is assumed that peripheral circuits such as a drive unit for controlling an image capturing cycle and the like are provided.

A frame image generating section 3 generates a luminance / color difference multiplex signal (hereinafter, referred to as a YUV signal) for each frame from an output signal of the image sensor 2. Here, a major reason for generating the YUV signal is to reduce (compress) the data amount. That is, the output of the image sensor 2 is the light primary color data (RGB data) itself,
Since this data is large in size and disadvantageous in terms of use of limited memory resources and processing time, it is necessary to reduce the data amount at least in some way. R data, G data, and B data) correspond to GY, R-
In addition to being able to be represented by three color difference signals of Y and BY, GY does not have to be transferred if the redundancy of these three color difference signals is removed, and GY = α (RY) −β (B −Y) (where α and β are synthesis coefficients), and by generating a YUV signal,
We are trying to reduce the amount of data.

The frame rate controller 4 switches the frame rate of the YUV signal output from the frame image generator 3 to one of two high and low frame rates in accordance with a predetermined control signal C_SEL. The high frame rate (hereinafter referred to as “high frame rate”)
The frame rate is the same as the frame rate of the YUV signal output from the frame image generation unit 3. Hereinafter, this high frame rate is assumed to be 30 frames per second for convenience of explanation. On the other hand, the lower frame rate (hereinafter referred to as “low frame rate”) is a frame rate lower than the above-described high frame rate. Hereinafter, this low frame rate is set to 15 frames per second, which is 1/2 of the high frame rate for convenience of explanation. The frame rate control unit 4 outputs a predetermined control signal C_
When the SEL is active, the frame rate is switched to the high frame rate, and when the predetermined control signal C_SEL is inactive, the frame rate is switched to the low frame rate.

The recording unit 5 is a recording medium for recording a moving image at a high frame rate or a low frame rate, and is, for example, a semiconductor storage device such as a flash memory or a magnetic recording device such as a flexible disk. Although a specific frame signal (that is, a still image signal) is also recorded in the recording section 5 as necessary, the description is omitted here because it is not related to the point of the present invention.

The sound level detector 6 includes a microphone 10
(Detection means) to detect a sound pressure level (hereinafter referred to as a "sound level") around (especially in the direction of the subject 9) picked up by the (detection means). And when a sound level exceeding the determination value is detected, the control signal C_SEL is activated,
Otherwise, the control signal C_SEL is made inactive and output.

FIG. 1B is a flowchart showing a main part of a "moving image photographing processing program" executed in the electronic still camera 1 having the above configuration. When this program is started, first, the sound level
The sound level in the direction is detected (step S11), and the sound level is taken into the frame rate judgment unit 7 and compared with the judgment value (step S12). When the sound level is higher than the determination value, the control signal S_SEL is activated and output. On the other hand, when the sound level is not higher than the determination value, the control signal S_SEL is inactive and output.

As described above, the frame rate control unit 4
Switches the frame rate to a high frame rate when the control signal C_SEL is active,
When the SEL is inactive, the frame rate is switched to a low frame rate. Therefore, in response to the active / inactive state of the control signal S_SEL, the recording unit 5 outputs the signal while the sound level is higher than the determination value. A moving image with a high frame rate is recorded (step S1).
3) As long as the sound level is not higher than the determination value, a moving image with a low frame rate is recorded (step S14).

Therefore, the above processing (step S11)
To the operation of step S14) to end the moving image shooting (step S14).
By repeating this process up to “YES determination” of No. 15), when a loud sound is heard from the direction of the subject 9, a moving image with a high frame rate can be recorded in the recording unit 5,
Otherwise, a moving image with a low frame rate can be recorded on the recording unit 5, so that the amount of recording data during the low frame rate period can be compressed, and the storage capacity of the recording unit 5 can be effectively used. In addition, the special effect that the moving image shooting time can be extended can be obtained.

FIG. 2 is a processing image diagram in the first embodiment. In this figure, the judgment value 11 is a predetermined constant value. While the sound level 12 detected by the sound level detection unit 6 is higher than the determination value 11 (see the hatched portion), the control signal S_SEL output from the frame rate determination unit 7 is active. Become active. The recording mode of the recording unit 5 is “high frame rate recording” while the control signal S_SEL is active, and the control signal S_SEL
Is "low frame rate recording" while is inactive.

Therefore, in the present embodiment, control signal S_SE output from frame rate
While L is active, that is, while the sound level 12 detected by the sound level detection unit 6 exceeds the determination value 11, a high frame rate moving image is recorded in the recording unit 5 (for example, In the example, the continuous frame image 14 is recorded on the time axis), while the control signal S_
While the SEL is inactive, that is, the sound level 12 detected by the sound level detector 6 is equal to the determination value 11.
Since the moving image at a low frame rate is recorded in the recording unit 5 (for example, in the example shown in the figure, intermittent frame images 13 and 15 are recorded on the time axis), It is possible to compress the recording data amount by the amount of the omitted frame image in the low frame rate recording mode.

In the present embodiment, since the microphone 10 and the sound level detector 6 are provided, voice recording may be performed using these components. Audio 1 in FIG.
Reference numerals 6 to 18 denote audio data recorded simultaneously in the recording unit 5.

FIG. 3 is a reproduction image diagram of a moving image recorded as described above. Here, the frame rate in the high frame rate recording mode is set to 30 per second in the NTSC specification.
Frames, and the frame rate in the low frame rate recording mode is set to 15 frames per second, which is 1/2 of the frame rate.
Assuming that the frame rate at the time of reproduction is 30 frames per second of the NTSC specification, the frame rate at the time of reproduction is uniformly applied to all recording frames regardless of the frame rate at the time of recording. For frames, n (n = 30 frames / 15 frames = 2) double-speed playback, and for high-frame-rate recording frames, single-speed playback. Eventually, low-frame-rate recording frames are fast-forwarded at double-speed playback. Can be.

Therefore, in the present embodiment, when a loud sound exceeding the determination value is not heard from the direction of the subject 9, the reproduction speed during the period is increased (n-times speed reproduction), while the reproduction of the subject 9 is performed. When a loud sound exceeding the determination value is heard from the direction, the effect that the sound can be reproduced at a normal reproduction speed (1 × speed) is obtained. For example, when the sound level from the subject 9 is increased. In this case, a specific effect is obtained in that the reproduction speed can be set to a normal speed (1 × speed) to perform detailed image observation.

In the above description, the sound level from the direction of the subject 9 is detected to change the frame rate at the time of moving image recording into two levels, high and low. However, the present invention is not limited to this. For example, the frame rate may be changed to three or more steps, or the frame rate may be changed linearly according to the sound level.

Alternatively, the frame rate may be changed by detecting a physical quantity other than the sound level. FIG.
(A) “moving image photographing processing program” that detects the luminance level of subject 9 and changes the frame rate
3 is a flowchart showing a main part of FIG. When the program is started, first, a luminance change determination area for designating which part of the subject 9 is to detect a luminance change is set (step S21). In this brightness change determination area setting, for example, as shown in FIG. 5A, the photographing range 20 of the image sensor 2 is divided into a large number of areas, and one or more of the areas are designated. . The hatched area in the figure represents the designated luminance change determination area 21, and the image included in this area 21 (in FIG. 5B, for convenience, the rear wheel 23 of the vehicle 22 is shown).
Is the luminance detection target image.

Next, the luminance level of the luminance detection target image is detected (step S22), and the detected luminance is compared with a predetermined judgment value (step S23). When the detected luminance is higher than the determination value, the control signal S_SEL is activated and output, and when the detected luminance is not higher than the determination value, the control signal S_SEL is inactive and output.

Therefore, as described above, the frame rate control unit 4 switches the frame rate to the high frame rate when the control signal C_SEL is active, and switches the frame rate to the low frame rate when the control signal C_SEL is inactive. Therefore, in the end, in response to the active / inactive state of the control signal S_SEL, a high frame rate moving image is recorded in the recording unit 5 while the detected luminance exceeds the determination value (step S24). As long as the luminance does not exceed the determination value, an effect that a moving image with a low frame rate is recorded (step S25) is obtained, and as a result, the operation of the above processing (steps S22 to S25) is completed. (“YES determination” in step S26). Can compress the amount of data recorded in Mureto period, by effectively utilizing the storage capacity of the recording section 5, it is possible to extend the moving picture photographing time.

FIG. 4B is a comparison image diagram of the detected luminance and the judgment value in step S23, where K0 is the judgment value, and Kn is the judgment margin. The detected luminance is determined by the determination value K
There are two types, namely, a high-luminance side and a low-luminance side with respect to 0. If the high-luminance side is K1 and the low-luminance side is -K1, in this comparative image, when K1 exceeds K0 + Kn, the frame rate is switched ( The effect of switching to a low frame rate (starting a low frame rate moving image) even when -K1 falls below K0-Kn is obtained. In this example, the same margin (K
n) is set, but is not limited to this. An individual margin suitable for each of the high luminance side and the low luminance side may be set.

FIG. 6A is a flowchart showing a main part of a "moving image photographing processing program" which detects the amount of movement of the subject 9 and changes the frame rate. When the program is started, first, a motion detection determination area for designating which part of the subject 9 to detect the motion amount is set (step S31). This motion detection determination area setting is performed, for example, by dividing the photographing range 20 of the image sensor 2 into a number of areas as shown in FIG.
Designate an area consisting of one or more of the areas. The hatched area in the figure represents the designated motion detection determination area 21.
(The image of the rear wheel 23 of the vehicle 22 for convenience in FIG. 5B) is the motion detection target image.

Next, the motion amount of the motion detection target image is detected (step S32), and the motion amount is compared with a predetermined judgment value (step S33). When the motion amount exceeds the determination value, the control signal S_SEL is activated and output. When the motion amount does not exceed the determination value, the control signal S_SEL is inactive and output.

Therefore, as described above, the frame rate control unit 4 switches the frame rate to the high frame rate when the control signal C_SEL is active, and switches the frame rate to the low frame rate when the control signal C_SEL is inactive. Therefore, in the end, according to the active / inactive state of the control signal S_SEL, a high frame rate moving image is recorded in the recording unit 5 while the amount of motion exceeds the determination value (step S34). As long as the amount does not exceed the determination value, an effect that a moving image with a low frame rate is recorded (step S35) is obtained, and as a result, the operation of the above processing (steps S32 to S35) is completed. To reduce the amount of data recorded during the low frame rate period Rukoto can, by effectively utilizing the storage capacity of the recording section 5, it is possible to extend the moving picture photographing time.

FIG. 6B is a flowchart showing a main part of a "moving image photographing processing program" which detects the intentional operation of the photographer and changes the frame rate. In this program, first, an intentional operation (for example, an ON / OFF operation of a “high frame rate recording button” provided in the electronic still camera 1) related to a change in the frame rate by the photographer is detected (step S41). And
When the button is turned on, the control signal S_SEL
Is activated, and when the button is turned off, the control signal S_SEL is made inactive and output.

Therefore, as described above, the frame rate control unit 4 switches the frame rate to the high frame rate when the control signal C_SEL is active, and switches the frame rate to the low frame rate when the control signal C_SEL is inactive. Therefore, in the end, in response to the active / inactive state of the control signal S_SEL, a high frame rate moving image is recorded in the recording unit 5 while the button is being turned on (step S42). During the OFF operation, the operation of recording a moving image with a low frame rate is obtained (step S43). As a result, the recording data amount during the low frame rate period can be compressed, and the recording unit can be compressed. 5 can be used effectively to extend the movie shooting time .

In the above description, (1) when a sound level exceeding the judgment value is detected, (2) when a luminance exceeding the judgment value is detected, and (3) when a motion amount exceeding the judgment value is detected. (4) Switching to the high frame rate recording mode (starting high-frame-rate movie shooting) at any time when the photographer's operation to change to the high frame rate is detected, Conversely, the mode may be switched to the low frame rate recording mode (moving image shooting at a low frame rate is started). Further, the determination value may be changed between when switching from a high frame rate to a low frame rate and when switching from a low frame rate to a high frame rate.

In the above description, the frame rate is changed when a sound level, luminance, motion amount, etc. exceeding the judgment value is detected. The frame rate may be changed when the amount exceeds (or falls below) a predetermined value. In the above description, the sound level is detected to change the frame rate. However, the sound quality may be determined by detecting the sound frequency, and the frame rate may be changed based on the sound quality. Good.

In the above description, the luminance, the amount of motion, and the like are detected by using the frame image acquired by the image sensor 2. However, a photo sensor and a motion detecting sensor are separately provided, and this sensor is used. Alternatively, the luminance and the amount of movement of the subject may be detected. Also, (1) when a change in sound level cannot be detected for a certain period of time, (2) when a change in luminance cannot be detected for a certain period of time, (3) when a motion amount cannot be detected for a certain period of time, (4) The switching to the high frame rate recording mode or the low frame rate recording mode may be performed at any time when the change operation by the photographer has not been detected for a certain period of time.

In the above description, the frame rate is changed by thinning out the frame images by the frame rate control unit 4. However, by controlling the exposure time and the exposure (photographing) interval of the image sensor 2, the frame rate is changed. The rate may be changed.

Alternatively, by modifying the above example, (1) when a sound level exceeding the judgment value is detected, (2) when a luminance exceeding the judgment value is detected, and (3) a motion amount exceeding the judgment value is obtained. (4) When any of the “time” when the change operation to the high frame rate is detected by the photographer,
A predetermined trigger signal for switching to the high frame rate recording mode (hereinafter, “high frame rate recording trigger signal”
That. ), And the recording frame rate may be maintained at a high frame rate until a predetermined time elapses from the generation of the trigger signal.

FIG. 7 shows the "moving image photographing processing program".
3 is a flowchart showing a main part of FIG. When the program is started, first, it is determined whether or not a high frame rate recording trigger signal is generated (step S51). If the trigger signal has not been generated, the moving image is recorded at a low frame rate (step S52). If the trigger signal has been generated, the timer is turned on (step S53), and the high frame rate is set. The moving image is recorded at the rate (step S54), and the high frame rate moving image recording in step S54 is continuously executed until the timer value matches or exceeds the predetermined determination value (step S55).

Therefore, according to this program, a predetermined high frame rate recording trigger signal is generated at any one of the above “time” and a predetermined time (timer time) elapses from the generation of the trigger signal. During the period (until the determination result of step S55 becomes “YES”), the moving image recording is performed at a high frame rate, so that one event (one of the above “time”) is made to respond. Switching to a high frame rate can be performed, and automatic return to a low frame rate can be performed after a lapse of a predetermined time from the occurrence of the event.

FIG. 8 is a diagram showing two images of frame rate switching. In the upper diagram (a), both the switching to the high frame rate and the return to the lower frame rate are controlled by a predetermined event (for example, a photographer's operation event), but in the lower diagram (b), Controls only switching to a high frame rate (or low frame rate) at a predetermined event (for example, a photographer's operation event), and automatically returns to a low frame rate (or high frame rate) by a timer operation. Therefore, the process of returning to the low frame rate can be simplified.

In the above description, a predetermined high frame rate recording trigger signal is generated at any one of the above “time”, and a predetermined time (timer time) elapses from the generation of the trigger signal. During this time, a moving image is recorded at a high frame rate. However, at any one of the above-mentioned “time”, a predetermined high frame rate recording trigger signal is generated, and a predetermined time (timer time) from the generation of the trigger signal is generated. After the elapse), recording of a moving image at a high frame rate may be started.

In the above description, the case where the moving image recording apparatus of the present invention is applied to an electronic still camera has been described. However, moving image data already recorded at a high frame rate is reproduced, and the above-mentioned (1) determination is made. When a sound level exceeding the judgment value is detected, (2) a luminance exceeding the judgment value is detected, (3) a motion amount exceeding the judgment value is detected,
(4) At any time when a change operation to a high frame rate is detected by the photographer, a predetermined trigger signal for switching to the high frame rate recording mode is generated to switch the frame rate and re-execute. The present invention can be applied to a moving image recording apparatus that performs recording.

<Second Embodiment> In the first embodiment described above, the frame rate of a captured image is changed and recorded as it is. However, the present invention is not limited to this mode.
For example, MPEG (Motion Picture)
Moving image compression technology such as Experts Group) may be used in combination.

Here, MPEG includes MPEG1 and MP.
There are schemes such as EG2. These schemes include transfer speeds (about 1.5 Mbit / sec for MPEG1 and several M to several tens Mbit / sec for MPEG2) and applicable objects (MPEG1 is mainly used for storing data on CD-ROM, etc.). Although there are differences in media systems and MPEG2 from storage media systems to broadcast / communication media such as next-generation televisions, etc., their compression technologies are DCT (Discrete Transform) and motion compensation (MC: Motion Compensation).
n) A common point is that a so-called hybrid coding scheme that combines inter-frame prediction is adopted.

DCT is an international standard for still image compression, also called discrete cosine transform, and is a method of encoding using the correlation between levels of adjacent pixels in an image. The transform coefficients are quantized and the quantization numbers are encoded. Since a still image has correlation in both horizontal and vertical directions, two-dimensional conversion is generally used. Image data is m pixels x n
The block is divided into line blocks, and the blocks are orthogonally transformed and quantized.

On the other hand, in a moving image (moving image), the current frame (current frame) and the immediately preceding frame (previous frame) are often similar except for a scene change due to editing. Is about 30 frames per second, and the change in the image for about 1/30 second is not always large, depending on the content of the image.

Therefore, in moving picture coding, past frames are used for predicting the current frame. However, the first frame (first frame) uses a still image coding method. The coding of a still image is not limited to predictive coding and transform coding, and data used in coding is closed within the image. No other image is used for prediction. For this reason, a method of encoding only from information in a frame is referred to as intra-frame encoding or intra-coding, and a frame encoded by that method is referred to as an “intra-coded frame” (intra-frame). coding
picture: "I" picture for short).

In moving picture coding, forward and bidirectional inter-frame prediction is used. The former is called inter-frame coding, and a frame coded by this method is referred to as an “inter-frame coded frame” (predictive frame).
-Coding picture: "P" picture for short). Also, the latter is called frame interpolation coding,
A frame encoded by the technique is referred to as a “frame interpolation encoded frame” (bidirectionally-
coding Picture: "B" picture for short).

FIG. 9 is a conceptual block diagram of a principal part of an MPEG processing unit in a conventional electronic still camera.
The MPEG processing unit 30 includes a buffer memory 31, first to fifth frame memories 32 to 36, a first prediction memory 37, a second prediction memory 38, a coded picture memory 39, a coded picture attribute schedule register 40, a coded picture It comprises an attribute register 41, a coded picture frame memory number register 42, a frame memory pointer 43, a control unit 44, and the like. The first to fifth frame memories 32 to 36 constitute a frame memory group 45, the first prediction memory 37 and the second prediction memory 38 constitute a prediction memory group 46, and the coded picture attribute schedule register 4
0, the coded picture attribute register 41, the coded picture frame memory number register 42, and the frame memory pointer 43 constitute a register memory group 47.

The control unit 44 controls the input / output of the buffer memory 31, the frame memory group 45, the prediction memory group 46, the register memory group 47, and the coded picture memory 39, and refers to the contents of the register memory group 47. While executing the state transition algorithm shown in FIG. In FIG. 10, each square indicates a state transition that changes from left to right as viewed in the drawing, and the number in parentheses at the beginning of each state line indicates a memory or a memory constituting the MPEG processing unit 30. It represents the sign of the register (see FIG. 9).

That is, the control unit 44 sequentially stores the frame images F0, F1, F3,... In the buffer memory 31, and stores the coded picture attribute scheduled data B0, B1,. I2, B3, B4,
Are sequentially stored. Here, “F” stands for frame, “B” stands for B picture, “I” stands for picture, and “P” stands for P picture. The control unit 44
Stores the encoded picture attribute data in the encoded picture attribute register 41 sequentially. Here, the encoded picture attribute data is 1 GOP (Group Of Pictu).
res) is referred to as “I, B, B, P, B, B, P,
B, B, P, B, B, P, B, B ". The control unit 44 sequentially stores the encoded picture frame memory number data M1, M1, M2, M1,... In the encoded picture frame memory number register 42, and stores the frame pointer data M1 in the frame memory pointer 43. , M2, M3, M4,... Are sequentially stored.
Here, “M” is an abbreviation for frame memory, and the number following M specifies the number of the frame memory.
For example, if it is M1, the first frame memory 32, M2
If so, the second frame memory 33 is specified.

The control unit 44 stores the frame images F0 and F in the first to fifth frame memories 32 to 36.
.. Are sequentially stored, and the storage position is designated by the frame pointer data. For example,
If the frame pointer data is M1, the contents (frame image) of the buffer memory 31 at that time are stored (saved) in the first frame memory 32. In the drawing, a circle symbol (丸) indicates a frame image to be subjected to the encoding process at that time. Also, the control unit 44
Data necessary for predicting a B picture or a P picture is stored in the first prediction register 37 and the second prediction register 38.

The control section 44 generates an intra-coded frame (I picture), an inter-coded frame (P picture) and a frame interpolated encoded frame (B picture) while controlling the data storage. Are sequentially stored in the coded picture memory 39, and the stored data is output as MPEG image data.

However, in the conventional MPEG processing unit 30, although the data compression effect inherent to MPEG is provided, the frame rate change control as in the first embodiment is not performed, so that a further data amount is required. The reduction effect cannot be expected, and there is room for improvement in this regard.

FIG. 11 shows an MPE according to the second embodiment.
FIG. 3 is a conceptual main block diagram of a G processing unit 50. In addition,
The same components as those in FIG. 9 are denoted by the same reference numerals. 9 is different from FIG. 9 in that a condition determination target memory number register 51 and an encoding flag register 52 are added to the memory register group 47, and the state transition algorithm shown in FIG. On the point.

The control unit 53 makes an “appropriate judgment” on the frame image indicated by the contents of the condition judgment target memory number register 51, and sets the encoding flag register 52 in the set state (according to the judgment result). "ON") or reset. The contents of the condition determination target memory number register 51 are the same as the contents of the previous frame memory pointer 43. Here, the “appropriate determination” refers to the determination of the sound level, the determination of the detected luminance, the determination of the amount of motion, or the determination of the intentional operation by the photographer in the first embodiment.

Although the content of the frame memory pointer 43 is the initial value M1, it does not always become a regular repetition of M1, M2, M3, M4 and M5 as in the prior art (FIG. 10). Basically, pointers (M1, M2,
When setting (M3, M4 or M5), a pointer that is larger than the current pointer value and is usable (in a hatched state) is set.

Incidentally, white square symbols (□) in the figure represent frame images that were not to be encoded in the above-described encoding discrimination, and black square symbols (■) represent frame images that were not encoded. Represents an image. By the way, the frame image of ■ needs to be held until the encoding process represented by the white circle symbol (○) is performed, and the frame memory pointer 43 is not targeted for the memory area of the frame image. Depending on whether the activation flag is established, random behavior will occur. For example, the operation of the frame images F9 (see ▼ in the figure) to F10 will be described. In this frame time, the value of the frame pointer 43 is M5
Therefore, the frame image F9 is stored in the fifth frame memory 3
6 will be stored. Next, the frame memory pointer 43 is updated to store the frame image F10. At this time, since M1 and M2 are storing the frame images (F5 and F6) to be encoded, the M1 and M2 are passed. Then, M3 is set in the frame memory pointer 43. As a result, the frame image F10 is stored in the third frame memory 34 (M3).

Therefore, by executing the state transition algorithm of FIG. 12 in the control unit 53, the coded picture memory 39 is intermittently skipped in some thinned state (see the arrow lines 61 to 64 in the figure). As a result of storing the coded pictures, an effect equivalent to changing the frame rate is obtained as in the first embodiment at the beginning, and MPEG
In addition to the data compression effect, the amount of moving image data can be further reduced.

<Third Embodiment> FIG. 13 is a conceptual main block diagram of an MPEG processing unit 70 according to the third embodiment. The MPEG processing unit 50 of the second embodiment is shown in FIG.
This is a modification of FIG. Note that the same components as those in FIG. 11 are denoted by the same reference numerals. 11 is different from FIG. 11 in that a write-back frame memory pointer 71 is added to the memory register group 47, and the first to third synthesizing memories 72 to 74 (collectively referred to as the synthesizing memory group 7).
6 is assumed. ) And the point that the control unit 76 executes the state transition algorithm shown in FIG.

The first compositing memory 72 is written with a frame image as a compositing reference. However, only one frame image immediately after the start of the operation is special because there is no frame before reference. Further, a frame image newly fetched for synthesis is written in the second synthesis memory 73, and the first synthesis memory 72 and the second synthesis memory 73 are stored in the third synthesis memory 74 within the frame time. Is written.

The write-back frame memory pointer 7
In 1, information indicating the number of frame memories (first to fifth frame memories 32 to 36) to which the contents of the third combining memory 74 are to be written back is written. For example, the operation of the frame images F9 (see ▼ in the figure) to F10 will be described. In the frame to which the frame image F9 is transferred, F6 ′ is stored in the first combining memory 72. At this time,
As in the second embodiment, it is determined whether or not the frame image F8 is to be encoded. Here, ■ indicates a frame determined to be encoded. Now, since the frame image F8 is an encoding target (■), the encoding flag register 52 is turned ON, and the frame image F8 is written in the second compositing memory 73. However, it is assumed that the encoding target frame is always written in the second combining memory 73.

At the same time when the frame image is written in the second synthesizing memory 73, the frame memory number (M4) in which the frame image (F8) is stored is written in the write-back frame memory pointer 71. First
The frame image (F
6 ') and "appropriate combining" are performed, and the combined frame image (F8') is written to the third combining memory 74. Here, “appropriate composition” refers to image composition of the entire frame image or image composition of only a part of the frame image. Subsequently, in the time zone of the frame image F10,
The frame image (F8 ') stored in the third combining memory 74 is transferred to the first combining memory 72, and is also written back to the frame memory indicated by the write-back frame memory pointer 71.

At the same frame time (F10), the encoding of the frame image F9 is also determined, and the frame image F9 is stored in the second combining memory 73 as an encoding target (■). The same processing as after the state stored in the second combining memory 73 is performed.
At this time, the frame picture F8 ′ is encoded (○), so that an I picture (I2) including the information of the frame pictures F5, F6, and F8 is generated. As described above, by generating the MPEG data by repeating the above operation, images that are successively combined can be recorded as a moving image.

Therefore, by executing the state transition algorithm of FIG. 14 in the control unit 76, the coded picture memory 39 is intermittently stored in a thinned-out state (see arrows 77 to 80 in the figure). As a result of storing the coded pictures, an effect equivalent to changing the frame rate is obtained as in the first embodiment at the beginning, and MPEG
In addition to the data compression effect, the amount of moving image data can be further reduced.

<Fourth Embodiment> FIG. 15 is a conceptual main block diagram of an MPEG processing unit 90 according to a fourth embodiment. The MPEG processing unit 50 according to the second embodiment is shown in FIG.
This is a modification of FIG. Note that the same components as those in FIG. 11 are denoted by the same reference numerals. 11 is different from FIG. 11 in that a control flag register 91 and a generated picture pointer 92 are provided in the memory register group 47, and the state transition algorithm shown in FIGS. 16 and 17 is executed by the control unit 93. On the point.

In FIGS. 16 and 17, the upper part (a) shows a state transition diagram when the control flag register 91 is not used (when the present invention is not applied) (hereinafter referred to as “state A”), and the lower part (b) shows FIG. 10 is a state transition diagram (hereinafter, referred to as “state B”) when a control flag register 91 is used (when the present invention is applied). State B relates to the fourth embodiment, and state A is for comparison.

First, the state A will be described. Frame images are fetched from the image pickup apparatus in the order of F0, F1, F2, F3,... -Fifth frame memory 32-36
Is written to. These frame images are designated according to the information pointed to by the generated picture pointer 92. The designated frame memories (first to fifth frame memories 32 to 36)
Is encoded with the designated picture attribute. For example, generated picture pointer 9
When the information indicated by 2 is “M3I”, the frame image (F3) stored in the third frame memory 34 is encoded as an I picture, the encoding result is written into the generated picture memory 39, and the first Prediction memory 3
7 is also written.

The control unit 93 generates a B picture by bidirectional prediction based on the information in the first prediction memory 37 and the second prediction memory 38. For example, in generating B3 corresponding to the time zone of the frame image F7, the frame image of F3 is encoded as a B picture (B3) from the image information of I2 of the first prediction memory 37 and P5 of the second prediction memory 38.

As described above, the generated picture pointer 92 is repeated for each GOP (15 frames in the figure), encodes an arbitrary frame image as an image having a desired picture attribute, generates a GOP, and generates an MPEG image. .

Next, the state B according to the present embodiment will be described. In the state B, the control flag register 91 is used. The control flag repeats ON / OFF for each frame after receiving a predetermined start trigger (see the above-mentioned “high frame rate recording trigger signal”). However, the default state is OFF. Now, assuming that a start trigger is received at the timing of the downward arrow symbol (↓) in FIG. 17B, the generated picture pointer 92 is not updated while the control flag is ON, and the frame image from the imaging device is not updated. Frame memory (first to fifth frame memories 3
2-36). Control flag is ON from ON
Upon returning to F, the same processing as in the state A is performed, the generated picture pointer 92 is updated, and the frame images from the imaging device are also stored in the frame memories (first to fifth frame memories 32 to 36). At the same time, encoding processing of the frame image is performed.

As described above, in the state B according to the present embodiment, the picture is not generated and the GOP is not written in the MPEG file when the control flag is ON. As in the embodiment, an effect equivalent to changing the frame rate is obtained, and the MP
Combined with the data compression effect of the EG, the amount of moving image data can be further reduced. Further, FIG.
As shown in (1), when the MPEG file generated in the state B is reproduced, the reproduction time can be shortened as compared with the state A, and an effect equivalent to fast forward can be obtained.

The state transition algorithm of the fourth embodiment may be modified as shown in FIG. In the state B of the fourth embodiment, the frame memory number indicated by the generated picture pointer 92 and the attribute of the generated picture are the same as those in the state A even when the start trigger occurs. In this modification, the frame image sent from the imaging device is not encoded every time, and the frame for which the picture is to be generated is skipped and encoded. Can be closed,
The independence of the GOP in the skip image can be maintained.

[0073]

According to the moving picture recording apparatus of the present invention, when the physical quantity representing the state of the subject meets a predetermined judgment condition or when a user's operation for changing the frame rate is detected, the frame is stored in the storage means. The frame rate of the moving image when storing and storing the image is changed. Therefore, the amount of photographing data during the low frame rate period can be compressed, and the moving image photographing time can be extended.

[Brief description of the drawings]

FIG. 1 is a simplified block configuration diagram of an electronic still camera according to a first embodiment.

FIG. 2 is a processing image diagram in the first embodiment.

FIG. 3 is a view showing a reproduction image of a moving image.

FIG. 4 is a flowchart showing a main part of a moving image photographing processing program for detecting a luminance level of a subject 9 and changing a frame rate, and a comparison image diagram of detected luminance and a determination value in step S23 of the flowchart.

FIG. 5 is a diagram showing a luminance change determination area 21 (or a motion detection determination area 21) and a diagram showing a luminance detection target image (or a motion detection target image).

FIG. 6 is a flowchart showing a main part of a moving image photographing processing program for detecting a motion amount of a subject 9 and changing a frame rate, and detecting a photographer's intentional operation to change a frame rate. It is a flowchart which shows the principal part of a moving image photography processing program.

FIG. 7 is a flowchart illustrating a main part of a moving image photographing processing program that maintains a recording frame rate at a high frame rate until a predetermined time has elapsed from the generation of a trigger signal.

FIG. 8 is a diagram illustrating two images of frame rate switching.

FIG. 9 is a conceptual block diagram of a principal part of an MPEG processing unit in a conventional electronic still camera.

FIG. 10 is a state transition diagram of MPEG processing in a conventional electronic still camera.

FIG. 11 shows an MPEG processing unit 50 according to the second embodiment.
It is a principal part block diagram of.

FIG. 12 is a state transition diagram of MPEG processing according to the second embodiment.

FIG. 13 shows an MPEG processing unit 70 according to the third embodiment.
It is a principal part block diagram of.

FIG. 14 is a state transition diagram of MPEG processing according to the third embodiment.

FIG. 15 shows an MPEG processing unit 90 according to the fourth embodiment.
It is a principal part block diagram of.

FIG. 16 is a state transition diagram of MPEG processing according to the fourth embodiment.

FIG. 17 is a state transition diagram of MPEG processing according to the fourth embodiment.

FIG. 18 is a transition diagram of a modified state of the MPEG processing according to the fourth embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Electronic still camera 2 Image sensor (acquisition means) 3 Frame image generation part (acquisition means) 4 Frame rate control part (storage control means, control means) 5 Recording part (storage means) 6 Sound level detection part (detection means) 7 Frame rate determination unit (control means) 10 Microphone (detection means)

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5C022 AA13 AC42 AC72 AC80 5C052 GA02 GB06 GB07 GC05 GE04 5C053 FA08 FA23 FA27 GA11 GA14 GB19 GB21 GB22 GB30 GB37 JA01 KA03 LA01 5C059 LB07 MA00 MA05 MA23 PP04 PP16 SS15 SS17 TA07 TA60 TB04 TC43 TD12 UA02 UA33 UA38

Claims (8)

[Claims] An acquisition unit configured to sequentially acquire a plurality of frame images constituting a moving image; a storage control unit configured to accumulate and store frame images sequentially acquired by the acquisition unit in a storage unit; Detecting means for detecting a physical quantity representing a state; and changing a frame rate of the moving image when storing and storing a frame image in the storage means when the physical quantity detected by the detecting means meets a predetermined determination condition. A moving image recording apparatus, comprising: a control unit. 2. The method according to claim 1, wherein the detecting unit detects, as the physical quantity, a sound level or sound quality emitted from the subject itself or around the subject, and the control unit determines that the sound level or the sound quality matches a predetermined determination condition. 2. The moving image recording apparatus according to claim 1, wherein a frame rate is changed. 3. The method according to claim 1, wherein the detecting unit detects a brightness level of the subject itself or a surrounding of the subject as the physical quantity, and the control unit changes the frame rate when the brightness level meets a predetermined determination condition. The moving image recording device according to claim 1, wherein: 4. The detecting means detects a motion amount of the subject itself or an object around the subject as the physical quantity, and the control means changes the frame rate when the motion quantity meets a predetermined determination condition. The moving image recording apparatus according to claim 1, wherein 5. The apparatus according to claim 1, wherein said control means includes means for changing said frame rate when said physical quantity no longer meets a predetermined determination condition. The moving image recording device according to claim 4. 6. The apparatus according to claim 1, wherein said control means includes means for changing said frame rate after a lapse of a predetermined time after said physical quantity meets a predetermined determination condition. The moving image recording device according to claim 3 or 4. 7. An acquisition unit for sequentially acquiring a plurality of frame images constituting a moving image, a storage control unit for accumulating and storing frame images sequentially acquired by the acquisition unit in a storage unit, and changing a frame rate by a user. Detecting means for detecting an operation, and control means for changing a frame rate of the moving image when storing a frame image in the storage means when a change operation is detected by the detecting means. Moving image recording device. 8. The storage unit stores an encoded frame image including an intra-coded frame, an inter-coded frame, and an interpolated encoded frame, and the control unit controls the encoding process. And turning on and off the frame rate of the moving image when storing the frame image in the storage means. The moving picture recording device according to claim 5, claim 6, or claim 7.