JPH05111057A - Recording/reproducing device - Google Patents

Abstract

PURPOSE:To reduce recording density without deteriorating the subjective resolution of stereoscopic vision by compressing two video signals by respectively different prescribed compression rates. CONSTITUTION:At the time of recording, two video signals are respectively stored in frame memories 12, 13 and successively compressed by a prescribed method while controlling their compression rates by a controller 15. In this case, one video signal is compressed within a range in which the deterioration of picture quality can not be recognized and the other video signal is compressed by a compression rate different from that of the former one while permitting a certain degree of deterioration in picture quality. The compressed data are recorded in a magnetic tape 19 through an error correcting code adding part 16 and a record modulating part 17. At the time of reproducing, video signals restored by an image extending part 22 after prescribed processing are stored in respective frame memories 23, 24 in accordance with their sorts and then simultaneously read out and outputted. Consequently the volume of data to be recorded can be reduced degrading without the evaluation of stereoscopic vision.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording / reproducing apparatus capable of recording a video signal in a binocular stereoscopic view.

[0002]

2. Description of the Related Art A first conventional example relating to an analog recording VTR will be described. FIG. 4 shows a configuration example of an analog recording VTR as a recording / reproducing device for recording a video signal of a two-eye stereoscopic view.

The two video signals respectively input from the input terminals 10 and 11 are input to the video signal selection section 12. The video signal selection unit 50 outputs one of the video signals input based on a predetermined cycle by the controller 56 to the signal processing unit 51. The controller 56 outputs the switching signal to the video signal selecting unit 50, and at the same time, outputs it to the signal processing unit 51 to record the switching signal if necessary. The signal output from the signal processing unit 51 is recorded on the magnetic tape in the recording / reproducing unit 52. The recording / reproducing unit 15 may have the same structure as a commercially available normal VTR. In the reproducing operation, the signal output from the magnetic tape in the recording / reproducing unit 52 is subjected to necessary processing in the signal processing unit 51, and the output terminal 54
More video signal is output. Further, the switching signal extraction unit 53
Then, a switching signal for the reproduced image is generated and the switching signal is output from the output terminal 55. As a method of reproducing the switching signal, in addition to the method of reproducing from the signal recorded exclusively, the reproduction from the video signal may be performed. In the first conventional example, two video signals for the right eye and the left eye are displayed in a time division manner. As an example of the time division method, FIG.
You can think of the street.

The system shown in FIG. 5A is a system in which even and odd fields of a video signal are assigned to two video signals, respectively, and the video signal to be recorded is switched for each field. This method has an advantage that recording and reproduction can be performed in the same signal form as a normal video signal, but since only one field of information is recorded on one screen, the vertical resolution is halved. there were.

The method of FIG. 5B is a method of switching the video signal to be recorded for each frame so that both fields of one screen can be recorded so as to make up for the drawbacks of the method of FIG. 5A. is there. However, in this method, the screen can be displayed only once in two frames, so that there is a drawback that flicker increases and the resolution in the moving direction deteriorates.

Next, a second conventional example will be described. Second
FIG. 6 shows an overall block diagram of the conventional example. Second
The conventional example can be commonly applied to an analog recording VTR and a digital recording VTR. In the case of analog recording, an analog video signal is input to the input terminals 10 and 11, and in the case of digital recording, a digital video signal is input. Is entered. The video signal is time-axis compressed to half by the time-axis compression units 60 and 61, and then multiplexed into one signal by the time-axis multiplexing unit 62. The multiplexed signal is recorded on the magnetic tape after being subjected to modulation necessary for recording in the recording / reproducing unit 52.

Next, the operation during reproduction will be described. The signal read from the magnetic tape is demodulated in the recording / reproducing unit 52 and then divided into two video signals by the time axis dividing unit 63. Since the two video signals are in the time-axis compressed state, they are returned to the original time-axis in the time-axis expansion units 64 and 65 and output to the output terminals 25 and 26 at the same time. FIG. 7 shows an example of a video signal recording method in the second conventional example. Each video signal is compressed by half in the time axis, and two video signals are alternately recorded.

In the second conventional example, it is systematically possible to record all two video signals in order to solve the problem of the first conventional example. However, for that purpose, it was necessary to double the consumption amount of the magnetic tape or double the signal recording density. There is a problem that the recording time is reduced when the tape consumption amount is increased. When the recording density is increased, there is a problem that the image quality is deteriorated in analog recording and the error rate is deteriorated in digital recording.

[0009]

Conventionally, in order to record two pieces of image information for stereoscopic vision, it is necessary to allow deterioration in resolution temporally or spatially or to achieve a high recording density. There was no problem. It is an object of the present invention to provide a recording / reproducing apparatus capable of reducing recording density without deteriorating quality such as subjective resolution in stereoscopic vision.

[0010]

In order to achieve the above-mentioned object, according to the present invention, two coded video signals are processed by a high-efficiency coding technique so that the image quality of the first video signal is improved. It is compressed to a first compression rate (1 / M) within a range where no deterioration is recognized, and some deterioration in image quality is recognized for the second video signal, and then the second compression rate (N Compress to 1). At this time, the first compression rate and the second compression rate are different from each other.

[0011]

The compression of data by the high efficiency coding technique is very useful for reducing the recording density. However, if the compression rate is increased, the image quality will start to deteriorate, and if the compression rate is further increased, the image quality will gradually deteriorate.

In one- and two-lens stereoscopic vision, if the image quality of one image is good to some extent, even if the image quality of the other one is somewhat poor, it will not affect the overall image quality. Therefore, by increasing the compression ratio of one video signal, it is possible to reduce the amount of data to be recorded without degrading the evaluation for stereoscopic vision.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an overall block diagram of an embodiment of the present invention.

The operation during recording will be described. The two video signals are input from the input terminals 10 and 11, and the data are stored in the frame memories 12 and 13, respectively. Next, the two video signals are sequentially compressed at a predetermined compression rate at an image compression rate of 14. Diffuse cosine transform or the like can be applied to the compression method, but the compression method is not specified. The two video signals are sequentially compressed by the image compression unit 14 by a predetermined method. Various compression methods can be considered. For example, there is a discrete cosine transform method. What is the discrete cosine transform method?
In this method, one screen is divided into blocks of about 8 × 8, discrete cosine transform is performed on the blocks, and the transformed data is appropriately quantized to be compressed. The compression rates of the two video signals are controlled by the controller 15. The compressed data is the error correction code addition unit 1
Data for correction is added in 6 and converted into a signal form suitable for the recording / reproducing system in the recording / modulating unit 17, and then recorded on the magnetic tape 19 by the magnetic head 18.

At the time of reproduction, the signal read from the magnetic tape 19 by the magnetic head 18 is demodulated by the demodulation section 20 and input to the error correction section 21. The error correction unit 21 uses the data added by the error correction code addition unit 16 to correct and detect the error generated in the recording / reproducing system.
The corrected data is restored to the original video signal in the image decompression unit 22, and recorded in the frame memory 23 or 24 depending on the type of the video signal. Frame memory 23, 2
Two video signals are read out simultaneously from No. 4 and are simultaneously output from the output terminals 25 and 26, respectively.

There is a method of displaying, for example, as shown in FIG.
According to this method, polarizing plates 32 having different polarization characteristics are provided on the front surfaces of the display device 30 for the right eye and the display device 31 for the left eye.
33 is installed and the two images are combined by the half mirror 34. The observer wears the spectacles 35 to which the polarizing plate is attached. The polarization characteristics of the polarizing plates attached to the eyeglasses 35 are different between the left and right, and a polarizing plate having the same polarizing characteristics as the display device 30 for the right eye is attached to the right eye and the display device 31 for the left eye is attached to the left eye. There is. Table 1 shows the data amount before and after the compression when the data amount (1.0) of the image of one frame before the compression is used as a reference. Table 1 is a table showing the amount of data before and after compression by each method when the amount of data (1.0) of the image of one frame before compression is used as a reference.

[0017]

[Table 1]

The first method is an example in which the total amount of data after compression is made equal to the amount of data of a single image that has not been compressed. As an example of the compression rate, the first video signal is set to three quarters.
In addition, it is possible to compress the second video signal to 1/4. The characteristic of this method is that it is possible to commonly use a VTR for recording without compressing one video signal and a recording / reproducing system.

The second method is an example in which the total amount of data after compression is made smaller than that of a single image data which is not compressed. As an example of the compression rate, a case where the first video signal is compressed to 1/4 and the second video signal is compressed to 1/10 can be considered. Since the feature of this method is that the amount of data to be recorded can be greatly reduced, it is possible to achieve a lower recording density, a longer recording time, etc., as compared with other methods.

The third method is a method of compressing only the second video signal without compressing the first video signal. According to this method, it is possible to configure a common recording format when recording only one video signal and when recording two signals. An example of the format structure is shown in FIG. The first video signal is sent to the video block 41 and the second video signal is sent to the second
The video signal of is recorded in the video block 40. The audio signal is recorded in the audio block 42. When only one video signal is recorded, the block 40 can be used for multiple purposes such as multi-channel audio signals and still image information without being used for the video signal.

Humans do not use their right and left eyes equally and have a dominant eye. Individuals have different dominant eyes. If a video signal with a high compression rate is selected with respect to the video signal for the dominant eye, the video with poor image quality is mainly viewed, and the subjective evaluation as stereoscopic vision becomes low. Therefore, the overall quality of the stereoscopic image can be improved by alternately switching the compression rates for the two video signals. As the switching frequency, a field frequency, a frame frequency, every other scanning line, or the like can be used. However, it is desirable to set it so that flicker due to switching is not felt. The present invention is not limited to the above embodiment.

In the above-described embodiment, the compression method for the first video signal and the compression method for the second video signal are the same, but the compression method can be changed for each video signal. As an example, it is possible to use a method that utilizes the correlation between video signals, such as compressing the difference information between two video signals. This utilizes the fact that stereoscopic images have a very high correlation with each other. If one of the compressions is performed using this correlation, the video signal can be compressed more efficiently. That is,
If the first video signal and the second video signal have different compression rates, various compression methods can be used.

[0023]

As described above, according to the magnetic recording / reproducing apparatus of the present invention, the compression ratio of one video signal is made different from the compression ratio of the other video signal to evaluate stereoscopic vision. The amount of data to be recorded can be deleted without dropping.

[Brief description of drawings]

FIG. 1 is a diagram for explaining an embodiment of the present invention.

FIG. 2 is a diagram for explaining a display method according to an embodiment of the present invention.

FIG. 3 is a diagram showing a recording format in an embodiment of the present invention.

FIG. 4 is a block diagram of a recording / reproducing apparatus of a first conventional example.

FIG. 5 is a diagram for explaining a video signal recording method in a recording / reproducing apparatus of a first conventional example.

FIG. 6 is a block diagram of a second conventional recording / reproducing apparatus.

FIG. 7 is a diagram for explaining a video signal recording method in a recording / reproducing apparatus of a second conventional example.

[Explanation of symbols]

 10, 11 ... Video signal input terminals 12, 13 ... Input frame memory 14 ... Image compression unit 15 ... Controller 16 ... Error check code addition unit 21 ... Error correction unit 22 ... Image expansion unit 23, 24 ... Output frame memory 25, 26 ... Video signal output terminals 30, 31 ... Display device 32, 33 ... Polarizing plate 34 ... Half mirror 35 ... Polarizing glasses

Claims (1)

[Claims] 1. A recording / reproducing apparatus for recording and reproducing a first video signal and a second video signal for obtaining a stereoscopic video, wherein the first video signal is compressed at a first compression rate. First compression means, second compression means for compressing the second video signal at a second compression rate, second compression rate by the second compression means, and the first compression means And a control unit for controlling the first compression rate according to the above to be different from each other.