JPH0414685A - Moving picture signal recording and reproducing device - Google Patents

Abstract

PURPOSE:To record and reproduce a still picture with superior picture quality by applying an error correction code having superior error correcting performance than that for a moving picture signal to a still picture signal. CONSTITUTION:Signals inputted from a sound signal input part 1, a still picture signal input part 2 and a moving picture signal input part 3 are necessarily processed in filtration, relisting, band compression and time base adjustment, etc., by sound, still picture and moving picture signal input processors 4-6 respectively. Then, error correction coding is performed on these three signals by error correction coders 7-9. A code applied to the coder 8 for the still picture signal is superior in performance than the coder 9 for the moving picture signal. A selection of the still picture/moving picture is made by a signal changeover switch 10, and moreover by a signal changeover switch 11, a changeover of the sound/picture is performed in accordance with a recording format, and then the signal is modulated by a modulator 12 and outputted from an R/A output part 13 to be recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a moving image signal recording and reproducing apparatus for recording image information.

Digital recording VTRs are being developed as VTRs that do not suffer from deterioration caused by conventional dubbing techniques. Especially home digital VT
In R, in order to record on a small cassette for a long time, band compression is performed and then error correction encoding is performed before recording. When band compression is used, correction of errors is performed over a wide range rather than one pixel, making interpolation using surrounding pixels of the same frame or field difficult. Replacement with pixels at the same position in the previous and subsequent frames or fields is common. Also, filtering may be performed after replacement.

Problems to be Solved by the Invention However, when attempting to record a still image on a digital recording VTR using band compression as described above, it becomes impossible to correct errors because there are no previous or subsequent images. Further, in the case of a moving image, one image appears for only a few tenths of a second, but in the case of a still image, it remains visible for at least several seconds, and if there is an error, it will be very noticeable.

It is an object of the present invention to solve the problems that occur when recording still images on such a conventional digital recording VTR.

Means for Solving the Problems A first aspect of the present invention is a moving image signal recording and reproducing apparatus characterized in that an error correction code having a superior error correction ability for still image signals than for moving image signals is used. It is.

A second aspect of the present invention is a moving image signal recording and reproducing apparatus that records one still image signal multiple times.

A third aspect of the present invention is a moving image signal recording and reproducing apparatus characterized in that a recorded still image signal is repeatedly reproduced a plurality of times.

A fourth aspect of the present invention is a moving image signal recording and reproducing apparatus characterized in that, in a still image signal, a pixel or a group of pixels in which an error has been detected is corrected using neighboring pixels in the same frame or field. be.

Operation With the above-described configuration, when the first, second, and third aspects of the present invention are used, very efficient error correction is performed for still image signals compared to that for moving image signals, and errors are eliminated. It can eliminate the need for correction. Further, according to the fourth aspect of the present invention, even if an error is detected, it is possible to correct the pixel without making it noticeable.

Example The present invention will be explained below using examples.

FIG. 1 is a block diagram of an embodiment of the first invention. 1st
1 in the figure is an audio signal input section, 2 is a still image signal input section, and 3
is a moving image signal input section, 4 is an audio signal input processor, 5 is a still image signal input processor, 6 is a moving image signal input processor, 7
8 is an error correction encoder for audio signals, 8 is an error correction encoder for still image signals, 9 is an error correction encoder for moving image signals, 10 is a still/moving image signal switch, 1
1 is an audio/image signal switcher, 12 is a modulator, and 13 is an R/
A output section, 14 is an H/A input section, 15 is a demodulator, 16 is an error correction decoder for audio signals, 17 is an error correction decoder for still image signals, and 18 is an error correction decoder for moving image signals. 19 is an audio signal output processor, 20
21 is a still image signal output processor, 21 is a moving image signal output processor, 22 is an audio signal output section, 23 is a still image signal output section, and 24 is a moving image signal output section.

Signals input from the audio signal input section 1, still image signal input section 2, and moving image signal input section 3 are processed by an audio signal input processor 4, a still image signal input processor 5, and a moving image signal input processor 6, respectively. Necessary processing such as filtering, sorting, band compression, and time axis adjustment is performed. Thereafter, the signals are subjected to error correction encoding by an error correction encoder 7 for audio signals, an error correction encoder 8 for still image signals, and an error correction encoder 9 for moving image signals, respectively. Since still image signals require more powerful error correction capability than moving image signals, the code used in error correction encoder 8 is superior in performance to the code used in error correction encoder 9. It is something. A still/moving image signal switch 10 selects either a still image or a moving image, and an audio/image signal switch 11 switches audio/image according to the recording format. The signal modulated by the modulator 12 is output from the R/A output section 13 and recorded. The reproduced signal is input from the H/A input section 14, demodulated by the demodulator 15, and then processed by an error correction decoder 16 for audio signals, an error correction decoder 17 for still image signals, and an error correction decoder 17 for moving image signals. The correction decoder 18 corrects and detects the respective signals. The audio signal output processor 19, the still image signal output processor 20, and the moving image signal output processor 21 perform inverse processing and modification of the processing such as filtering, rearrangement, band compression, and time axis adjustment performed at the time of input.
By outputting each signal from the audio signal output section 22, the still image signal output section 23, and the moving image signal output section 24, still images can be recorded and reproduced, and error correction can be reduced compared to the case of moving images. - In audio signal and video signal recording and reproducing devices used on boats, error correction codes for audio signals are required to have superior error correction ability compared to error correction codes for video signals, and error correction codes for still image signals are required. It is possible to use error correction codes for audio signals.

FIG. 2 is a block diagram of a second embodiment of the invention. Second
In the figure, 31 is a still image signal input section, 32 is a moving image signal input section, 33 is a still image signal input processor, 34 is a moving image signal input processor, 35 is a memory, and 36 is error correction encoding for the still image signal. 37 is an error correction encoder for moving image signals; 38 is a still image/moving image signal switch; 39
is a modulator, 40 is an R/A output section, 41 is an H/A input section,
42 is a demodulator, 43 is an error correction decoder for still image signals, 44 is a determiner, 45 is a memory, 46 is an error correction decoder for moving image signals, 47 is a still image signal output processor, and 48 is a moving image signal. The image signal output processor, 49 is a still image signal output section, and 50 is a moving image signal output section. Signals input from the still image signal input section 31 and the moving image signal input section 32 are filtered, rearranged, band compressed, time axis adjusted, etc. by a still image signal input processor 33 and a moving image signal input processor 34, respectively. processing is performed. For the still image signal, information for one image is stored in the memory 35 and the information is repeatedly output. Further, after being subjected to error correction encoding by an error correction encoder 36 for still image signals and an error correction encoder 37 for moving image signals,
Either a still image or a moving image is selected by the still/moving image signal switch 38, and the signal modulated by the modulator 39 is
It is output from the R/A output unit 40 and recorded. The reproduced signal is input from the H/A input unit 41, demodulated by the demodulator 42, and then sent to the error correction decoder 43 for still image signals.
, are respectively corrected and detected by the error correction decoder 44 for the moving image signal. Since the same data is recorded multiple times, the data obtained the first time is first stored in the memory 45, and each time the data obtained from the second time onwards, the corresponding data is read out from the memory 45, and the determiner 46 reads out the corresponding data. The data is determined based on a comparison, majority vote, or other judgment method, and the data is stored in the memory 4.
Re-memorize to 5. If necessary, data regarding the judgment situation is also stored.

Still image signal output processor 47, moving image signal output processor 4
By performing inverse processing and modification of the processing such as filtering, sorting, band compression, time axis adjustment, etc. performed at the time of input in step 8, and outputting each signal from the still image signal output section 49 and the moving image signal output section 50. Still images can be recorded and played back. When recording is performed a plurality of times in this way, the probability that an error will occur in all the same parts is very low, and there is almost no possibility of correcting the error.

In the present invention, for example, if one still image signal is recorded in N tracks or sectors, it is necessary to repeat it in units of N tracks or sectors that have information for one image, or to record the signal in each track or sector. The format of repeating in units is arbitrary.

FIG. 3 is a block diagram of a third embodiment of the invention. Third
In the figure, 61 is an H/A input section, 62 is a demodulator, 63 is an error correction decoder for still image signals, 64 is a determiner, and 65
is a memory, 66 is an error correction decoder for moving image signals, 67 is a still image signal output processor, 68 is a moving image signal output processor, 69 is a still image signal output section, 70 is a moving image signal output section, 71 is an error occurrence state determiner. The reproduced signal is input from the H/A input unit 61, demodulated by a demodulator 62, and then corrected and detected by an error correction decoder 63 for still image signals and an error correction decoder 64 for moving image signals. be done. Since the same data is reproduced multiple times, the data obtained the first time is first stored in the memory 65, and each time the data obtained from the second time onwards, the corresponding data is read out from the memory 65, and the determiner 66 reads out the corresponding data. The data is determined based on a comparison, majority vote, or other determination method, and is stored again in the memory 65. If necessary, data regarding the judgment situation is also stored. still image signal output processor 67;
The moving image signal output processor 68 performs inverse processing and modification of the processing such as filtering, rearrangement, band compression, time axis adjustment, etc. performed at the time of input, and outputs each signal from the still image signal output section 69 and the moving image signal output section 70. Still images can be reproduced by outputting signals. Furthermore, based on the error correction state of the error correction decoder 63 for the still image signal, an error state determiner 71 determines the error occurrence state of the reproduced signal, and feed-hacks the result to the system to control the number of reproductions. It is also possible to do so. When reproduction is performed a plurality of times in this way, the probability that an error will occur in all the same parts is extremely low, except for damage to the recording medium, and there is almost no possibility of correcting the error.

FIG. 4 is a block diagram of an embodiment of the fourth invention. Fourth
In the figure, 81 is a memory, 82 is a correction value calculator, and 83 is a selector. In a moving image signal, especially when band compression is performed, error correction is performed by replacing pixels at corresponding positions in the previous and subsequent screens with a group of pixels. This can be done simply by writing an error-corrected signal into a memory for one screen, and by disabling writing to the pixel or pixel group where an error has been detected. However, in the case of a still image, since there are no preceding or following screens, a circuit is required to correct errors by interpolating each pixel from surrounding pixels. A signal input per pixel and an error detection signal synchronized therewith are input to the memory 81, and a correction value calculator 82 outputs the signal to the memory 81.
A correction value for each pixel is determined based on the data from , and the selector 83 selects the correction value for the pixel detected as having an error, and selects the unchanged value for the other pixels. can be done. In order to perform such correction, better image quality can be obtained if no errors are detected in the surrounding pixels used for correction. On the other hand, in general recording and reproducing devices, errors may occur randomly, but they often occur consecutively. Therefore, in the actual recording space, it is desirable that each pixel be recorded at a position separate from the surrounding pixels used for correction, and on the recording side, shuffling, subsampling, etc. are used to rearrange the still image signal input. This can be achieved by having

In the embodiments of the present invention described above, the input/output processors for each signal are independent, but common parts can be shared. The same applies to the error correction coding/decoding device for each signal. Furthermore, it is possible to record audio signals when recording still images. The circuit configuration given in the above embodiment is just an example, and similar signal processing can be performed with a different configuration. The present invention is applicable to still images in any case, such as not performing band compression, performing upper band compression on moving images, or performing band compression at a compression rate different from that for moving images. Furthermore, it is possible to combine all or some of the first, second, third, and fourth aspects of the present invention.

As described in detail, according to the first, second, and third aspects of the present invention, much stronger error correction is performed on still image signals than on moving image signals, thereby eliminating errors. By eliminating the need for retouching, it is possible to record and play back still images of excellent image quality. Furthermore, according to the fourth aspect of the present invention, even when an error is detected, correction can be made without making the pixel stand out by finding a correction value from surrounding pixels.

As described above, by using the present invention, it becomes possible to record and reproduce high-quality still images using a moving image signal recording and reproducing apparatus.

[Brief explanation of drawings]

FIG. 1 is a block diagram of the first invention, FIG. 2 is a block diagram of the second invention, FIG. 3 is a block diagram of the third invention, and FIG. 4 is a block diagram of the fourth invention. It is a diagram. 7...Error correction encoder for audio signals, 8
...Error correction encoder for still image signals,
9...Error correction encoder for moving image signals;
10...Still/moving image signal switch, 11...
...Audio/image signal switcher, 16...Error correction decoder for audio signals, 17...Error correction decoder for still image signals, 18... Error correction decoder for moving image signals, 44.64...
...Judgment device, 45.65...Memory, 81.
...Memory, 82...Modification value calculator, 8
3...Selector. Name of agent: Patent attorney Shigetaka Awano (1 person) Figure 2

Claims (10)

[Claims] (1) A moving image characterized by having an error correction encoding means and an error correction decoding means constituting an error correction code having a better error correction ability for still image signals than for moving image signals. Image signal recording and reproducing device. (2) The moving picture signal recording and reproducing apparatus according to claim (1), wherein the same error correction code as that for the audio signal is used for the still picture signal. (3) recording means for recording one still image signal multiple times, and an image signal based on a signal that is error-corrected by reproducing the signal recorded multiple times and a detection signal by error correction decoding of the reproduced signal. 1. A moving image signal recording and reproducing apparatus, comprising a determining means for selecting a signal to be restored. (4) The moving picture signal recording and reproducing apparatus according to claim (3), further comprising a control means that can set the number of times of recording according to the error correction capability required of the still picture signal to be recorded. (5) For a still image signal, select a signal for restoring the image signal based on the error-corrected signal by repeatedly reproducing the recorded signal multiple times and the detected signal by error correction decoding on the reproduced signal. A moving image signal recording and reproducing device characterized by having a determining means. (6) The moving picture signal recording and reproducing apparatus according to claim (5), further comprising a control means that can set the number of times of reproduction according to the error correction capability required of the recorded still picture signal. (7) determining means for determining the error occurrence state of the reproduced signal;
6. The moving image signal recording and reproducing apparatus according to claim 5, further comprising a control means that can set the number of reproductions according to the error occurrence state. (8) In a still image signal, a moving image signal recording and reproducing device characterized by having an error correction means for correcting a pixel or a group of pixels in which an error has been detected using neighboring pixels in the same frame or field. . (9) input signal processing means that converts one still image signal into multiple frames or fields whose pixels are thinned out so that the positions of the pixels constituting each frame or field are different; 2. The present invention further comprises a modification means for performing modification using pixels that should be located around the pixel and that constitute a different frame or field when a pixel that requires modification occurs in the signal obtained by the above-mentioned signal. (8) The moving image signal recording and reproducing device as described. (10) The moving image signal recording and reproducing apparatus according to claim (8), further comprising input signal processing means for shuffling one still image signal.