JPH03209671A - Recording and reproducing device for static image signal - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a still image signal recording and reproducing apparatus that digitally records a high-definition still image signal on a recording medium such as an optical disc and reproduces the same.

Conventional Technology In recent years, filing systems that use large-capacity, compact optical disks as peripheral storage devices for computers, etc. have been announced one after another9, and the development of optical disk filing systems that can handle not only documents but also images is progressing. There is. In addition, in television technology, high-definition television (high-definition television), which has more than twice as many scanning lines and a wider aspect ratio than the conventional NTSC system, is attracting attention as a new next-generation television system. , VTRs that handle high-definition signals, video discs, and other equipment are being developed in a variety of fields.

Against this background, progress is being made in the development of a high-visibility optical disk filing system that records and plays back high-definition, realistic high-definition still image signals using optical disks with high recording density and quick search performance due to random access functions. For example, the analog method is
"High-Vision Optical Disc Image System" (for example, Morimoto et al.: Television Science and Technology Report VR8B-37), and digital systems such as "Development of High-Vision Television Photo System" (for example, Murakami et al.: Television Science and Technology Report VR8838) and "Digital High-Vision System" (for example, Murakami et al.: Television Science and Technology Report VR8838). Stanstem" (for example, in the column: Television Science and Technology Report VR883), etc.

A conventional still image signal recording and reproducing device will be described below with reference to the drawings. FIG. 2 is an example of a still image signal recording and reproducing apparatus that digitally records and reproduces high-definition still images.

First, signal recording will be explained. A high-definition signal sent from a high-definition camera is digitized by being quantized into m bits by an A/D converter 2 via an input terminal 1, and then frozen by a frame memory 3 to extract one frame from a moving image. Extract still images for 30 minutes.

The image signal stored in the frame memory 3 is processed by the image processing section 4.
Desired signal processing such as band compression is performed on the signal, and then the signal is stored in the Hanwha memory 5. The image signal output from the buffer memory 5 is converted from a parallel signal to a serial signal by adding various control signals and error correction codes necessary for recording the image signal on an optical disk in the recording processing section 7. Thereafter, digital modulation is performed, and the image data is recorded on a recording medium such as an optical disk by the recording/reproducing section 8.

On the other hand, during playback, the image data previously recorded on the recording medium is played back by the recording/playback unit 8, and after being digitally demodulated by the playback processing unit 9, contrary to the recording process, it is converted from a serial signal to a parallel signal. The data is subjected to desired error correction processing and the like, and is temporarily stored in the Hanwha memory 5. The reproduced signal outputted from the buffer memory 5 is subjected to signal processing opposite to that applied during recording in the image processing section 4, and then written back to the frame memory 3 described above. The image signal written in the frame memory 3 is converted into an analog signal by a D/A converter 12 and displayed on a high-definition display or the like via an output terminal 13.

Normally, when handling image signals as digital signals, A/
The number m of quantization bits quantized by the D converter is 8, and the digital signal processing system performs parallel processing using 8 bits as a basic unit.

A high-definition signal is a luminance signal (Y signal) that indicates the luminance component.
and two types of color difference components (P8 signal and P8 signal)
The conventional example described here also uses an 8-bit Y signal, a PB-multiplied signal P, and 8 bits each of the signals in parallel from the camera, display, etc. input/output interface part to the frame memory 3. The Y signal, P8 signal, and PR signal are processed sequentially from the output of the frame memory 3 during recording to the input of the recording processing section 7, or from the output of the reproduction processing section 9 during playback to the frame memory 3. Although it is processed, the unit of processing is still 8-bit parallel. - Recording on the destination disk is performed as a serial signal by subjecting an 8-bit parallel signal to parallel-to-serial conversion, and reproduction is performed by subjecting the serial signal to serial-to-parallel conversion to become an 8-bit parallel signal.

Problems to be Solved by the Invention In the above example, since the image signal signal of the digital signal processing unit is processed in parallel using the quantization bit number of 8 as a basic unit, when reproducing the image signal, the optical disc Because the signals are read out after serial-parallel conversion, it is impossible to configure one pixel until all eight consecutive signals are read out.

From the above, when performing search processing on this device that handles high-definition signals with an extremely large amount of information, if you try to perform continuous high-speed playback that corresponds to the search often used in video playback processing, the screen The problem is that it takes a considerable amount of time to perform the switching.

In view of this, an object of the present invention is to provide an apparatus that can reproduce high-definition signals at high speed even when image signals are continuously reproduced in search processing or the like.

Means for Solving the Problems According to the present invention, when recording a signal on a recording medium, the upper bit part of an 8-bit signal constituting one pixel of an image signal is left and the lower bit part is removed, or the lower bit part is removed. A bit number dividing circuit that removes the upper bit part while leaving the bit part, and distinguishes the upper bit part and lower bit part of the digital signal that makes up one pixel that is divided and recorded when playing back from a recording medium. and a control circuit that controls the operations of the bit number division circuit and the signal arrangement circuit. .

According to the above-described configuration, the present invention records a digital signal constituting one pixel by dividing it into its upper bit part and lower bit part, and when performing normal reproduction, both of the divided signals are reproduced. By configuring pixels using these elements, it is possible to reproduce one frame of still images without sacrificing the high definition of high-definition. In addition, when performing continuous high-speed reproduction, by configuring a pixel only from the upper bit part of the digital signal that constitutes one pixel,
One frame of a still image can be constructed by reproducing a signal with a smaller amount of information than the conventional method, and therefore it becomes possible to continuously reproduce still images at short intervals.

EXAMPLE An example of the present invention will be described below with reference to the drawings. FIG. 1 shows a schematic block diagram of a still image signal recording and reproducing apparatus according to the present invention. Parts that have almost the same functions as the conventional example are given the same numbers as the conventional example. During recording, the high-definition signal sent from the high-definition camera is input to the A/ The process from being quantized to m bits by the D converter 2 to being stored in the buffer memory 5 is the same as that described in the description of the prior art, and will therefore be omitted here.

The output signals of the buffer memory 5 are a Y signal indicating a luminance component, a P8 signal and a PR signal indicating two types of color difference components, and are input to the bit number division circuit 6 in a plane sequential manner (frame sequential manner). The bit number division circuit 6 first removes the lower (m - n) bits of the signal stored in the buffer memory 5 and is composed of m bits/2 bits per pixel, and converts only the upper n bits into a luminance signal. The three color difference signals are guided to the recording processing section 7 in order.

After the transfer of the upper n bits is completed, the lower n bits (m
−n) Only the brightness signal is the bit signal.

The color difference signals are guided to the recording processing section 7 in the order of color difference signals. Here, no particular mention is made of the recording order of the two types of color difference signals (PB multiple signal and P signal). The control such as the removal of the lower bits and upper bin t- and the ordering of the luminance signal and the color difference signal as described above is performed by a control signal from the control circuit 11.

The signal whose bit number has been reduced by the bit number dividing circuit 6 is processed in a recording processing section 7 in the same manner as in the conventional example, and the recording/reproducing section 8 records image data on a recording medium such as an optical disk.

FIG. 3 shows the recording order when recording image signals in comparison with that of a conventional example. The signal recording order in the present invention is shown in FIG. 3a, and the signal recording order in the conventional example is shown in FIG.

On the other hand, during playback, the image data previously recorded on the recording medium is played back by the recording/playback unit 8, and after being digitally demodulated by the playback processing unit 9, contrary to the recording process, it is converted from a serial signal to a parallel signal. The signal is then subjected to desired error correction and the like, and then input to the signal arrangement circuit 10. At the time of recording, the luminance signal and color difference signal of the upper bit part are recorded in the order, followed by the luminance signal and the three color difference signals of the lower bit part, so at the time of reproduction, the signals are reproduced in the order in which they were recorded at the time of recording.

In the case of normal playback, the signal placement circuit 10 switches the signals to be placed at predetermined positions in the buffer memory 5 according to the order in which they are played back, and all signals are stored in predetermined positions in the buffer memory. Recorded at the time of
It is assumed that the signal reading procedure in the reproducing unit 8 is completed.

On the other hand, if higher-speed reproduction than normal is required, the signal readout procedure in the recording/reproducing section 8 is performed once the luminance signal and color difference signal of the upper bit part are stored in a predetermined position in the buffer memory 5. Complete. Therefore, in this case, the reproduction is completed in a time of 07 m compared to the normal reproduction. In addition, as a second embodiment of high-speed reproduction, if even faster reproduction than the previous embodiment is required, if the image display is allowed to become monochrome, only the luminance signal of the upper bit part will be transferred to the buffer memory 5. If it is assumed that the signal reading procedure is completed when the signal is stored in a predetermined position in the recording medium, the time required to read the signal from the recording medium is shortened to 1/2 of the time required for high-speed color reproduction. In the case of high-speed playback, since signal reading from the recording medium is interrupted during normal signal reading, the signal is not written to the buffer memory 5 after the interruption, and the signal is not written to the buffer memory 5. There is a possibility that contents written during past processing remain. Therefore, it is clear that when performing high-speed reproduction, it is necessary to set the contents of the buffer memory 5 to a constant value (for example, O) in advance. The operation of the signal selection circuit 10 described above is controlled by a control signal from the control circuit 11.

The signal stored in the buffer memory 5 has a configuration of one pixel m
It is regarded as a normal image signal consisting of bits, and is then subjected to the same processing as in conventional devices, converted to an analog signal by the D/A converter 12, and displayed on a high-definition display or the like via the output terminal 13. .

As for the specific hardware configuration, for example, m is 8 and n is 4.
It is appropriate to divide the image signal constituting one pixel into upper 4 bits and lower 4 bits/7 bits.

When digitizing an image signal, it is usually quantized to 8 bits, and the upper bit part and lower bit part are divided into the same number, which simplifies signal processing such as bit removal and bit composition. be able to. Of course, other combinations will rank higher.

It is clear that it is also possible to separate the lower bit part and the lower bit part.

In reality, when handling high-definition signals as digital signals, the effective number of pixels is 1920 horizontal samples (luminance signal).
;960 samples (color difference signal).

Since there are 1035 vertical lines and 8 bits of quantization, the amount of information constituted by each signal is as follows.

Luminance signal (Y signal) 1920 x 1035 x 8 = 1589760
0 bit color difference signal (P8 signal) 960 x 1035 x 8 = 7948800 bit color difference signal (PR signal) 960 x 1035 x 8 = 7948800 bits total 31795200 bits...approximately 3.8 megabytes First embodiment of high-speed reproduction using the present invention Now, it is only necessary to read the signal for the upper 4 bits from the recording/playback unit 8, so luminance signal (Y signal) 1920 x 1035 x 4 = 7948800
Bit color difference signal (PB double signal 960 x 1035 x 4 = 39744003974
400 bit signal) 960 x 1035 x 4 = 39744003974
400 bits 7600 bits...approximately 1.9 megabytes, the amount of information is half that of normal playback.

In addition, in the second embodiment of high-speed reproduction, only the upper 4 bits of the luminance signal need be read out from the recording/reproducing section 8, so the luminance signal (Y signal) 1920x1035x 4-7948800 bits...
- The amount of information is approximately 0.95 megabytes, which is half of that of the first embodiment of high-speed playback.

In addition to the above-mentioned method, if the image processing section performs information compression processing on the signal, the actual time required for reproduction can be further reduced. The above explanation is illustrated and expressed in FIG. 4A shows the readout range of the image signal from the recording/playback section 8 in the case of normal playback, and the readout range in the case of color high-speed playback is shown in FIG. 4C. is the readout range for monochrome high-speed playback.

On the other hand, from the viewpoint of image quality deterioration, it is recommended to replace the signal with one that constitutes one pixel using only the upper 4 bits, that is, to leave the upper 4 bits as they are and to change the lower 4 bits to 0 to 1.
Fixing the value to a certain value (for example, 0) out of 5 obviously causes deterioration in image quality. Therefore, there are problems with normal playback using signals in this format.
If the usage conditions are limited, for example, if this device is used as a file device for an image database, or if it is used for special recursions such as continuous high-speed image searches during a search, it is better than the conventional method than the disadvantage of deteriorating image quality. The advantage of enabling even higher speed playback is far greater, and the high speed playback method according to the present invention is very effective.

Effects of the invention A device according to the present invention! In the case of normal reproduction, all the digital signals constituting one pixel are used to reproduce a high-definition still image without image quality deterioration, and in the case of high-speed reproduction, especially continuous high-speed reproduction, the digital signals constituting one pixel are used. Although there is some deterioration in image quality by using only the upper bit part, it is now possible to reproduce high-definition still images in less than half the time compared to the conventional method, and overall, the practical effects are great.

[Brief explanation of drawings]

FIG. 1 is a schematic block diagram of the entire device according to an embodiment of the present invention, FIG. 2 is a schematic block diagram of a conventional device, and FIG.
FIG. 4 is an explanatory diagram comparing the recording order of image signals in the recording/reproducing section between the present invention and a conventional example, and FIG. 4 is an explanatory diagram showing the signal readout range from the recording medium by various reproduction methods. 1... Input terminal, 2... A/D converter, 3... Frame memory, 4... Image processing unit, 5...・Buffer memory, 6...
・Bit number division circuit, 7...recording processing section, 8.
... Recording/playback section, 9... Playback processing section,
10... Signal placement circuit, 11... Control circuit, 12... D/A converter, 13...
・Output terminal.

Claims (5)

[Claims] (1) A still image signal recording device that digitally records a high-definition still image signal on a recording medium such as an optical disc, which records an image signal quantized into m bits as a signal component of upper n bits and a lower (m-bit) signal component. n) comprising at least a bit number division circuit that divides the signal into bit signal components and a control circuit that controls the signal division procedure in the bit number division circuit;
The method is characterized in that an upper n bit part and a lower bit (m-n) part of an image signal are recorded separately, and the image signal divided and recorded by the means is reconstructed and reproduced by a signal arrangement circuit. Still image signal recording and reproducing device. (2) As a recording method for high-definition still image signals to be recorded on a recording medium such as an optical disc, an image signal quantized to m bits is combined with the upper n bit signal component and the lower (m-bit) signal component.
n) Separating into bit signal components, further separating into a luminance signal component and a color difference signal component, dividing and recording each signal part, and reconstructing and reproducing the image signal recorded by the above means. The still image signal recording and reproducing apparatus according to claim 1, characterized in that: (3) A reproducing device for high-definition still image signals digitally recorded on a recording medium such as an optical disc,
A signal in which an image signal quantized into m bits is separated into an upper n-bit signal component and a lower (m-n) bit signal component, and the recorded image signals are combined and placed in the original m-bit signal. A still image signal reproducing device comprising at least a placement circuit and a control circuit for controlling a procedure during signal placement. (4) A reproducing device for high-definition still image signals digitally recorded on a recording medium such as an optical disc,
4. The still image signal reproducing apparatus according to claim 3, wherein during image reproduction, only the signal portions of the upper n bits of the luminance component and color difference component of the separately recorded image signal are reproduced. (5) A still image signal reproducing device that reproduces a high-definition still image signal digitally recorded on a recording medium such as an optical disk, in which the luminance component of the divided and recorded image signal components is 4. The still image signal reproducing apparatus according to claim 3, wherein only the upper n bits of the signal are reproduced.