JPH0795860B2 - Digital video signal recording / reproducing method and reproducing apparatus thereof - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital video signal recording / reproducing method and a reproducing apparatus thereof, and more particularly to a pixel data group formed by digital pulse modulation of an analog color video signal such as a high definition image signal. The present invention relates to a digital video signal recording / reproducing method in which a header signal is recorded together with graphic data and a reproducing apparatus capable of suitably reproducing an already recorded signal.

2. Description of the Related Art So-called high-definition television systems (hereinafter also referred to as high-definition systems), which are capable of transmitting much higher definition and higher quality than current color television systems (NTSC, etc.), are more popular than before. Is being researched. This high-definition television signal (high-definition signal) has, for example, 1125 scanning lines, a field frequency of 60 Hz, a luminance signal band of 20 MHz, and color signals of a wide band color signal of band 7.0 MHz and a narrow band color signal of band 5.5 MHz. Two types are transmitted. There are some prototypes for recording this high-definition signal which is an analog signal on a video disc. They have an extremely wide frequency band in which the high-definition signal is 5 to 6 times as wide as the current color television signal as described above. Therefore, recording is performed after band compression is performed by a technique such as Nyquist sampling and frame correlation. Further, when reproducing the video disc, the reproduced high definition signal is obtained by demodulating the reproduced video signal and then expanding the band.

Problems to be Solved by the Invention However, there is a problem that the circuit configuration for band compression and expansion described above is extremely complicated and expensive. On the other hand, a digital audio signal may be recorded with a digital video signal relating to a color still image that plays a supplementary role for aiding the imagination of a listener who listens to the reproduced sound of the digital audio signal. There is no conventional digital audio disc reproducing apparatus for reproducing a digital video signal obtained by digital pulse modulation (PCM, etc.) of the signal together with an audio signal, and a recording medium (especially digital audio) on which such a high-definition signal is temporarily recorded. -When playing back a disc, compatibility with the current playback device cannot be achieved unless the playback device can identify whether the played digital video signal is a high-definition signal.

Furthermore, if a wideband high-definition signal as described above is recorded without band compression, the transmission time will take, for example, about ten seconds, so it takes time until a high-definition image is displayed when cueing is performed by random access. However, it is preferable for the listener that an image that can be quickly reproduced during the recording is recorded.

In view of the above, the present invention solves the above problems by recording and reproducing a header signal that defines a reproduction condition together with a pixel data group, and further, a digital video signal recording / reproducing method which also satisfies the above requirements. It is an object of the present invention to provide the reproducing device.

Means for Solving the Problems A digital video signal recording / reproducing method according to the present invention is a digital video signal recording / reproducing method in which a header signal is time-division multiplexed in an image data group. A first pattern indicating whether or not the pixel data transmitted following the fixed signal in the first word and the header signal in the subsequent word relates to the high definition image.
And a second code indicating whether the pixel data is a normal color image or a monochrome image, and color pixel data designating the color of the monochrome image itself or the background color thereof. The pixel data group is recorded on the recording medium as a component encoded signal of a first luminance pixel data group and two types of color pixel data groups when the analog video signal relates to the color image, and the analog video signal is recorded. Is related to the monochromatic image, it is recorded on the recording medium as a second luminance pixel data group, and at the time of reproduction, reproduction pixels are stored in a memory designated based on the first and second codes of the reproduced header signal. Data is written, the accumulated pixel data is read from the memory, converted into an analog signal, and then displayed.

Further, the digital video signal reproducing device according to the present invention is
Reproducing means for reproducing the digital video signal from the recording medium, and header signal detecting means for detecting the header signal in the reproduced digital video signal taken out by the reproducing means and decoding the following first and second codes respectively. An image memory and a graphic memory for storing the pixel data group, and a pixel data group relating to a high-definition color image in the reproduced digital video signal based on the output signal of the header signal detecting means at a specified address in the image memory. And a second writing means for writing the pixel data of the monochromatic image in the reproduced digital video signal to the graphic memory only when the header signal detecting means detects that the pixel data is a monochromatic image. First reading means for reading pixel data accumulated in the image memory, and accumulation in the graphic memory Second reading means for obtaining pixel data in which the raw data and the pixel data based on the color pixel data in the header signal are time-division multiplexed, and the output pixel data of the first or second reading means is converted into an analog signal. And means for generating a reproduced video signal from the converted analog signal.

Operation When the analog video signal is a high-definition color image signal (high-definition signal), the wide-band luminance signal and the two kinds of color signals are separately digital pulse-modulated (PCM, etc.) to form a first luminance pixel data group. Two types of color pixel data groups are formed, which are time-sequentially combined as component encoded signals. Further, a header signal defining the reproduction condition of each pixel data group is time-division multiplexed in the component coded signal by a plurality of words, and the time-division multiplexed signal is recorded on a recording medium (disk, tape, etc.). Also,
When the analog video signal is a monochromatic image signal, a second luminance pixel data group obtained by digital pulse modulating the analog video signal is recorded together with the head signal. In the header signal, the background color of the monochromatic image signal or Color pixel data to be the color of the monochrome image itself is also included and recorded. here,
When the above background color is displayed, the luminance signal of the background is also included in the header signal, but when recording and reproducing by specifying each color of the single color pixel data, the header signal includes the color pixel data related to the hue. Only included and recorded. This is because the second luminance pixel data is recorded separately from the header signal.

At the time of reproduction, the header signal in the reproduced digital video signal is detected by returning to the synchronization signal of the fixed pattern, the kind of pixel data group following the header signal is identified from the first and second codes, and Accordingly, the pixel data is written in the memory. The pixel data written in the memory is read at a predetermined sampling frequency, digital-analog converted, and then displayed.

In the digital video signal reproducing device, the reproduction pixel data following the reproduction header signal is written to a predetermined memory address by the first writing means, and the reproduction digital video signal is reproduced by the second writing means only when the image is a monochrome image. The pixel data inside is written in the figure memory. And, it has means for reading out the pixel data accumulated in the pixel memory or the graphic memory and converting it to an analog signal, and means for generating a reproduced video signal from the converted analog signal, and the reproduced digital video signal is changed based on the header signal. Transmission is possible during the period when a certain display is possible or the pixel data group of the high definition image signal, which takes a long time to transmit due to the large number of pixels, is being written to the image memory for the reproduction display. Single-color images (figures,
Characters, record numbers, or combinations of these) can be displayed.

Embodiments Embodiments of the present invention will be described below with reference to the drawings.

1 and 2 show an embodiment of the signal format of a digital video signal recorded and reproduced according to the present invention. As shown in both figures, the header signal 1 consists of 6 words, and 1 word consists of 16 bits. Each word is transmitted in bit order from the most significant bit (MSB) to the least significant bit (LSB), and the header signal 1 is sequentially transmitted from the first word to the sixth word. The header signal has a signal format as shown in FIG. 1 and has a pixel data part (image data part) following one vertical line segment or one horizontal line segment.
Specifies the transmission / playback conditions for images to and from. As shown in FIG. 1, the pixel data section 2 has a signal format in which two pieces of pixel data each having a quantization bit number of 8 bits are arranged in one word.

Here, as described above, the high-definition image signal (high-definition signal) is composed of a luminance signal of band 20 MHz and a band of 7.0 MHz.
Of the wideband chrominance signal and the narrowband chrominance signal of 5.5 MHz, of which the luminance signal is the first sampling frequency f _S (eg, 51.788 MHz which is 1536 times the horizontal scanning frequency f _H ).
Are sampled and then quantized into a luminance pixel data group having a quantization bit number of 8 bits. The wideband color signal and the narrowband color signal each have a frequency f _S / 2 (for example, a frequency of 768 f _H 25.
After being separately sampled at a second sampling frequency of 894 MHz), they are separately quantized to form first and second color pixel data groups having a quantization bit number of 8 bits. In Fig. 1, the part indicated by 2a
Y ₀ , Y ₁ , Y ₂ , ... are the above luminance pixel data, C _W0 , C _W1 , ... _Are the first color pixel data relating to the above wide band color signal, C _N0 , C
_N1 , ... Is the second white pixel data relating to the narrow band color signal. That is, as can be seen from FIG. 1, the luminance pixel data is arranged in the upper 8 bits of each 1 word.
Alternatively, the second color pixel data is arranged in the lower 8 bits of each one word, and the first and second color pixels are alternately arranged for each word.

By the way, the number of scanning lines of a high-definition signal is 1125, and the number of effective scanning lines is about 1024. Also, the number of pixels (the number of sampling points) of the luminance signal per scanning line is obtained by dividing the sampling frequency f _S (here, 1536 · f _H ) by the horizontal scanning frequency f _H , and becomes, for example, 1536. . However, there are pixels in the horizontal blanking period in addition to the pixels of the image information, and the horizontal and vertical synchronizing signals can be added by the reproducing thread, and in view of saving the memory capacity of the reproducing system. The minimum necessary number of pixels of image information can be set to 1280 excluding the pixels in the horizontal blanking period. Therefore, the number of luminance pixel data for one scanning line is 1280, and the number of first and second color pixel data is 640 because each sampling frequency is half that of the luminance pixel data. Becomes Since the luminance pixel data is arranged in the upper 8 bits of each word of the pixel data section 2 as shown in FIG. 1, the pixel data section 2 subsequent to the header signal 1 is a high-definition signal for one horizontal scanning line. In the case of pixel data, the pixel data section 2 has 1280 words as shown in FIG. Therefore, 1
In the frame, as shown in FIG. 3, an image 10 having 1280 words in the horizontal direction and 1024 lines in the vertical direction is recorded in the signal format as shown in FIG.

It should be noted that in the present invention, pixel data relating to a monochrome image signal is also recorded and reproduced. This single color image is an image of a figure, a character, a symbol or a combination thereof (hereinafter, these are collectively referred to as "figure" for convenience in this specification),
The luminance signal has a band of 20 MHz and is quantized after sampling at the sampling frequency f _S , but the number of quantization bits is 4 bits, which is different from the luminance pixel data of the high-definition signal (natural image). . Therefore, as for the luminance pixel data (graphic data) regarding this graphic, four graphic data are arranged in one word as shown by 2b in FIG. Therefore, the transmission time of this graphic data does not transmit color pixel data, and the number of quantization bits is 4 bits, which is half the luminance pixel data of a natural image which is a color image. 4 is enough.

The number of one scanning line segment of this figure data is 1125 above.
In this method, the same 1280 pixels as the above luminance pixel data, but 4 pixels are transmitted in 1 word as shown by 2b in FIG. 1, so the graphic data for one scanning line is 320 (= 1280/4). It will be transmitted in words. The 6-word header signal is time-division multiplexed and recorded immediately before each 320-word graphic data group.

Next, the header signal will be described. As shown in FIGS. 1 and 2, the header signal 1 is a signal for defining the reproduction condition of the pixel data part 2 of one horizontal scanning line segment (or one vertical line segment) immediately after that, and the first word 3 A fixed pattern synchronization signal is placed in the header signal, and if the value is "FFFF" in hexadecimal notation, this header signal is used by using the transmission channel for 2 channels out of the 4 channels transmission channel of the digital audio disk described later. And immediately after that, one vertical line segment or one horizontal line segment digital video signal (pixel data) is transmitted. When "FFFF", it is transmitted using one of the four channel transmission lines. Indicates that

An identification signal is arranged in the second word 4. In this identification signal, the system code of the pixel data unit 2 is arranged at the position indicated by 4a of the MSB of the second word and the next second bit, a total of 2 bits. In this system code, the pixel data of the pixel data section 2 is a standard color video signal of a system with 625 scanning lines, a high-quality (high-definition) image signal with, for example, 1125 scanning lines,
It is identified whether it is a facsimile signal of a fine graphic or an original picture of a photograph, and computer data such as a character code or graphics data. Further, a transmission method identification code for identifying whether the pixel data is baseband pixel data or compressed pixel data obtained by compressing a full frame image into a half frame is arranged in the third bit 4b of the second word. The compressed pixel data is composed of only odd field data at odd-numbered sampling points and even field data at even-numbered sampling points in horizontal scanning, and is transmitted in half the time as compared with full-frame pixel data. The full-frame pixel data is taken into the memory circuit in the reproducing device as it is. On the other hand, the compressed pixel data is fetched at a predetermined address of the memory circuit, and the pixel data not transmitted at the time of reproduction is replaced by reproducing any one of the transmission pixel data around it, so-called staggered reproduction or the surrounding area. Interpolation is performed using the data obtained by calculating the transmission pixel data of. Although the arithmetic data of the compressed pixel data is accompanied by the signal deterioration due to the generation, the image transmission period can be halved, and the image memory amount can be halved when the dedicated reproducing device is constructed.

Position 4c of total 2 bits of 4th and 5th bits of 2nd word
For the time being, it is considered as a spare and no identification code is placed.
Positions 4d, 4e and 4 of 1 bit each of the following 6th, 7th and 8th bits
Codes for identifying the memory scan, the frame start, and the frame end are arranged in f, respectively. In the above memory scanning, the pixel data of the pixel data unit 2 is transmitted in the order of pixels along a horizontal scanning line (horizontal scanning) in the screen, or in the order of pixels along a vertical direction (vertical scanning). Is written and the write address to the memory is changed accordingly.

Furthermore, the 2nd bit position of the 9th and 10th bits of the second word 4
An identification code of a memory (write memory) to which pixel data is to be written and an identification code of a memory (read memory) to be read are arranged at 2-bit position 4h of 4g, the 11th and 12th bits. Of the 2nd bit arranged in this 4h, 1 bit on the MSB side is used for the luminance signal image memory and 2 bits.
Each of the two memory circuit units of the image memory for the color signal of one kind is instructed which one should be read out, and one bit of the LSB side indicates which one of the two memory circuit units of the graphic memory 49 should be read out. Further, at the 1-bit positions 4j, 4k, and 4l of the 14th, 15th, and 16th bits, an image mute,
Graphic mute and each color identification code are placed. The color designation identification code at the 4l position is the background color of the graphic image based on the monochromatic image data or the color of the graphic image itself (character color).
To identify. The 13th bit position indicated by 4i is reserved and is not used for the time being. The following table summarizes the relationship between the contents of the 10 types of identification codes in the second word 4 and the positions.

Next, in the two words of the third word 5 and the fourth word 6 of the header signal 1 shown in FIG. 1, 11-bit address and 10-bit address are arranged, respectively. Here, the 11-bit address signal arranged in the third word 5 indicates the X address of the memory to be written, and the 10-bit address signal arranged in the fourth word 6 indicates the Y address of the memory.
The address is indicated.

Further, in the lower 8 bits of the fifth word 7 and the lower 8 bits of the sixth word 8 of the header signal 1, a wide band color relating to the background color of the graphic image based on the monochromatic image data or the color of the graphic image itself (character color) Color pixel data of 8 bits of quantization bits of the signal C _W and the narrow band color signal C _N are arranged. Further, in the upper bits of the sixth word 8, the luminance pixel data of the background color of 8 quantization bits is arranged only when the background color is designated. The brightness pixel data and the brightness pixel data of the character color relating to the graphic image are as shown by 2b in FIG.
It is arranged in the pixel data unit 2. The digital video signal composed of the header signal 1 and the pixel data portion 2 of the above signal format is further time-division multiplexed with another information signal in a predetermined block unit and then recorded on a recording medium (for example, a disk). .

Next, a recording system according to the present invention will be described. FIG. 4 is a block system diagram of an embodiment of an image recording apparatus, FIG. 5 is a block system diagram of an embodiment of an image formatting unit, and FIG. The block system diagram of an example of a disk recording system main part is shown. The image recorded by the image recording apparatus shown in FIG. 4 is converted into the format shown in FIGS. 1 and 2 by the apparatus shown in FIG. 5, and then recorded on the disc by the recording system shown in FIG. . In Fig. 4, the image to be recorded (still image or partial moving image, natural image or monochromatic figure)
Is converted into an electric signal (video signal) by a high-definition camera 11 or a high-definition teloper 12 and supplied to a switcher 13, where one or a composite image is selectively output. The color video signal extracted from the switcher 13 is
A high-definition signal with 1125 scanning lines and a field frequency of 60 Hz, which is digital pulse modulated by the A / D converter 14 and converted into image data (pixel data) with a quantization bit number of 8 bits, and then a frame memory 15 And stored here. The pixel data group read from the frame memory 15 is supplied to the monitor TV 17 after being converted into an analog color video signal by the D / A converter 16.
The image content is checked here. If the result of the check is good, the pixel data group read from the frame memory 15 is digitally recorded as an image rush on the magnetic tape by the VTR 19 via the PCM processor 18.

The magnetic tape thus obtained is then reproduced by the VTR 20 shown in FIG. 5, and the reproduced signal is a PCM processor.
After being converted into the original pixel data group by 21, the data is written on the first magnetic disk of the magnetic disk device 23 through the computer 22. By inputting image transmission and reproduction conditions to the computer 22 from the input device 24,
A reference numeral 22 indicates a header signal having the signal format shown in FIG.
The recording pixel data group of the first magnetic disk in 23 is recorded on the second magnetic disk while time-editing. Also,
When the compressed image is recorded, the pixel data group reproduced from the first magnetic disk is recorded on the second magnetic disk while being compressed by the computer 22. This second
The header signal and the pixel data reproduced from the magnetic disk are sequentially read out and supplied to the PCM processor 25, where an error correction code and an error check code are added, and the number of scanning lines is 525. It is time-axis compressed so as to be transmitted within the video period of the video signal, supplied to the VTR 26 together with the time code, and recorded on the magnetic tape.

The recording signal of the magnetic tape recorded by the VTR 26 is reproduced and further converted into a digital video signal of the signal format shown in FIG. 2 through a known PCM processor and supplied to the format conversion circuit 30 from the input terminal 28 shown in FIG. It Further, the digital audio signal reproduced from the master tape in synchronization with the reproduced digital video signal is supplied to the format conversion circuit 30 via the input terminal 29. The format conversion circuit 30 generates and outputs a digital signal which is time-sequentially combined in block units of the signal format shown in FIG.

Here, in the signal of one block shown in FIG. 7, S indicates the arrangement position of the synchronization signal of an 8-bit fixed pattern indicating the start of the block. Ch-1, Ch-2, Ch-3, and Ch-4 respectively indicate the arrangement position of one word of a 16-bit digital signal (that is, the digital audio signal and digital video signal) of each one of the four channels. .

Further, P and Q shown in FIG. 7 are 16-bit error correction codes, respectively. Further CRC is a 23 bit error detection code, Ch-1~Ch-4, P arranged in the same block, obtained when dividing each word of the Q for example, ^{X 23 + X 5 + X 4} + X + 1 becomes generator polynomial It is a 23-bit remainder, and the signal from the 9th bit to the 127th bit of the same block is divided by the generator polynomial at the time of reproduction, and when the remainder obtained by this is zero, it is detected as no error. Used for. Further, in FIG. 7, Adr indicates a 1-bit multiplex position of various control signals (address signals) used for random access or the like. This control signal distributes each bit data,
One bit is transmitted in a block, for example, 196 blocks transmit all bits of the control signal (that is, the control signal is composed of 196 bits).

Further, U is 2 bits for backup called a user's bit, which transmits a language for connecting a computer to the reproducing apparatus to perform an interactive operation, for example. Then, one block of signal is composed of a total of 130 bits from S to U shown in FIG. 7, and the digital signal is combined in block units at a frequency of 44.1 KHz and transmitted in time series. The above 196-bit control signal is 4
This is a configuration in which four kinds of 9-bit address codes are combined in time series, and all these four kinds of address codes have the same signal format.

In this way, among the signal transmission paths of a total of 4 channels of Ch-1 to Ch-4, for example, the digital audio signal has a sampling frequency of 44.1 kHz, a quantization bit number of 16 bits, and Ch-1 and
The header signal 1 and the pixel data unit 2 are arranged in two words indicated by Ch-2 and transmitted, and Ch-3 and Ch-
They are arranged in 2 words indicated by 4 and transmitted sequentially.

The digital signal taken out from the format conversion circuit 30 in time series in the block unit of the signal format as shown in FIG. 7 is supplied to the scrambled NRZ modulator 31 shown in FIG. Other signals except for are subjected to scrambled NRZ modulation by addition of a signal (for example, M sequence code) from a preset random number table and modulo 2, and then supplied to the FM modulator 32. F
The frequency-modulated digital signal extracted from the M modulator 32 is supplied to a known cutting machine via an output terminal 33, converted into a modulated light beam, and then focused and irradiated on a tourist agent on the disk-shaped recording master. It A large number of discs (digital audio discs) can be duplicated by passing the disc-shaped recording master disc through known developing and disc-making processes.

By the way, the pixel data group of the above-mentioned natural image is recorded in the transmission channel of 2 channels among the transmission channels of the channels Ch-1 to Ch-4 in the signal format shown in FIG.
When reproduced, one frame is transmitted with 1286 × 1024 words as shown in FIGS. 2 and 3,
The transmission time (reproduction time) is 14.93 (= (1286
÷ 2) × 1024 ÷ (44.1 × 10 ³ )) seconds.
Therefore, when the above digital audio disc is randomly accessed, a high-definition color still image (natural image) cannot be obtained until 14.93 seconds after the desired information signal is cued.

Therefore, in the present embodiment, graphic data having a transmission time of 1/4 of the transmission time of the pixel data group of the natural image (thus, 3.75 seconds) is recorded and reproduced. As a result, the image non-display period after cueing by the above random access can be shortened to 3.75 seconds, which is 1/4, and this graphic data is used until a high-definition color still image (natural image) is obtained. Others are preferable because they can be displayed as a single-hue but high-quality graphic image. Furthermore, by displaying / non-displaying a graphic at an arbitrary time within the total transmission time of both images of 18.75 (14.93 + 3.75) seconds, it is possible to perform reproduction display with a considerable change.

Next, the reproducing apparatus of the present invention capable of performing the above-mentioned reproduction will be described with reference to the lock system diagram shown in FIG. An FM signal reproduced by a known means from the above-mentioned digital audio disc is FM-transmitted through the input terminal 40 shown in FIG.
The signal is supplied to the demodulation circuit 41, FM demodulated here, and then supplied to the decoding / error correction circuit 42, where descrambling, decoding and error correction are performed, and Ch-1 in the signal format shown in FIG. It becomes the reproduced digital signal assigned to Ch-4. The reproduced digital signal relating to the image among these is supplied to the distributor 44 and the header detection circuit 45 in the high-definition decoder 43, respectively. The distributor 44 supplies the upper 8 bits of the luminance pixel data of each word of the pixel data section 2 to the image memory 46, and the lower 8 bits of the color pixel data of each word are alternately supplied to the image memories 47 and 48 for each word. Distribute and supply. Further, the distributor 44 supplies each word 16 bits of the pixel data section 2 to the graphic memory 49. Therefore, the image memory 46 is supplied with the luminance pixel data, both image memories 47 are supplied with the first color pixel data, and the image memory 48 is supplied with the second color pixel data. The graphic data and the like are supplied to the graphic memory 49.

On the other hand, the header detection circuit 45 uses the first 1 of the header signal 1.
The header signal is detected by detecting the sync signal 3 having a fixed pattern of words, the identification code in the following 5 words is decoded, and the screen address signals are obtained. These signals are written to the write address generator 50. The pixel data is supplied and the output write address is controlled to write each pixel data to a specified address in a specified memory.

That is, the header detection circuit 45 uses a 16-bit shift register or the like to detect the first 1 of the header signal 1 shown in FIG.
When the sync signal placed in word 3 is detected, the next 5 words are fetched and the upper 2 bits 4a of second word 4 are fetched.
Only when the value of is "01" indicating high definition image data,
The contents of the following bits and words are decoded to control the write address generator 10 and the like, but when the image data is not high definition image data, writing to the memories 46 to 49 is prohibited, for example. When the image data in the input reproduced digital signal is high definition image data, the one of the memories 46 to 19 to which high definition image data is to be written depends on the value of 2 bits 4g in the header signal. The write address starting from the write address by the third word and the fourth word in the header signal is output from the write address generator 50 and writing is performed. The image memories 46 to 48 and the graphic memory 49 each have two memory circuits each having a capacity capable of storing pixel data and graphic data for one frame. Normally, one of them reads the pixel data being displayed on the display device and the other one. Is either writing the pixel data to be displayed next or not doing anything. However, wipe switching can be done by writing new pixel data in the memory circuit on the display side.
When the above pixel data is reproduced in the order according to the scanning line (horizontal scanning), the screen is switched in the vertical direction, and when it is reproduced in the direction orthogonal to the scanning line (vertical scanning). The screen switches to the left and right.

First, a case where the reproduced pixel data is image data (image data) regarding a high-definition color still image (natural image) will be described. In this case, one frame of luminance pixel data is written to the image memory 46, and one frame of first and second color pixel data is written to the image memories 47 and 48 separately. On the other hand, the read address generator 51 generates a read address based on the signal from the sync signal generator (SSG) 52, and outputs it to the image memories 46 and 47.
And 48 respectively, the pixel data of the third type separately stored in the image memories 46, 47 and 48 are read simultaneously or in parallel, and the sampling frequency of the pixel data is converted and output. If the read pixel data is luminance pixel data, the sampling frequency is set to, for example, 51,788
In the case of the first and second color pixel data, the sampling frequency is read out at 25.894 MHz. Pixel data is read out in the horizontal scanning direction of the screen.

The three types of pixel data read out simultaneously and in parallel from the display side memory circuit units of the image memories 46, 47 and 48 are individually supplied to the muting circuits 53, 54 and 55. The muting circuits 53, 54 and 55 use the header detection circuit 45 to decode the image mute code at the position 4j in the header signal to obtain the image memories 46, 4
A switch operation is performed to selectively output either the reproduced output image data 7 and 48 or the pixel data from the background color generation circuit 56. As will be described later, the background color generation circuit 56 generates luminance pixel data and two types of color pixel data, which are the background color, based on the fifth and sixth words in the header signal from the header detection circuit 45 when reproducing the graphic data. Output. The background color is specified as an arbitrary negative color during recording.

Here, since the reproduced pixel data is related to the natural image, the muting circuits 53, 54 and 55 output the image memories 46, 47 and
The reproduction output pixel data of 48 is selectively output as it is and individually supplied to the switching circuits 57, 58 and 59. In addition,
The muting circuit 60 is muting the output of the graphic memory 49 at this time. The switching circuit 57 selectively outputs either the output pixel data of the muting circuit 53 or the output graphic data of the muting circuit 60 based on the output signal of the graphic data detection circuit 61 described later, and the switching circuits 58 and 59 are Figure data detection circuit 61
One of the color pixel data from the muting circuits 54 and 55 or the color pixel data from the graphic color generation circuit 62 described later is selectively output based on the output signal of the. Here, since the reproduced pixel data relates to the natural image, the switching circuits 57, 58
From 59 and 59, the respective read output pixel data of the image memories 46, 47 and 48 which have individually passed through the muting circuits 53, 54 and 55 are selectively output and individually supplied to the DA converters 63, 64 and 65, Here, the digital-to-analog conversion is made into a digital signal.

The analog luminance signal extracted from the DA converter 63 is supplied to the synchronizing signal adding circuit 66, where the synchronizing signal from the SSG 52 is added, and then output to the output terminal 69 as a reproduction luminance signal. In addition, the DA converters 64 and 65
The first and second analog color signals are added with horizontal and vertical sync signals from the SSG 52 in the sync signal adding circuits 67 and 68, and output to the output terminal 70 as a reproduction broadband color signal, and a reproduction narrow band color. It is output to the output terminal 71 as a signal.
These output signals are passed through a decoder (not shown) to become the high definition image signal (high definition signal).

Next, a case where the reproduced pixel data is pixel data (graphic data) relating to a high-quality monochromatic graphic will be described. In this case, the muting circuits 53, 54 and 55 are controlled so that the background color generation circuit 56 selectively outputs the luminance pixel data regarding the background color and the two types of color pixel data. On the other hand, in the graphic memory 49, the reproduced graphic data having a quantization bit number of 4 bits is written for one frame. Further, based on the read address from the read address generator 51, the sampling frequency is converted to the 51.788 MHz from the display side memory circuit section side in the figure memory 49, and the figure data read out is further muted circuit 60. Are supplied to the switching circuit 57 and the graphic data detection circuit 61, respectively.
The figure data detection circuit 61 compares the value of the input pixel data with the reference value, and when the value of the input pixel data becomes equal to or more than the reference value, the muting circuit 60 is compared with the switching circuits 57, 58 and 59. Then, a switching signal for selectively outputting the output pixel data of the graphic color generating circuit 62 is generated and output, and when it is smaller than the reference value, the switching circuit 5
A switching signal is generated and output to 7,58 and 59 to selectively output the output pixel data of the background color generation circuit 56 that has passed through the muting circuits 53,54 and 55.

Here, the reference value in the figure data detection circuit 61 is
Since the figure data having the quantization bit number of 4 bits has 16 gradations, it is selected as a value indicating 8 gradations of the midpoint gradations.
Therefore, when the figure data has a value of 8 gradations or more, the reproduced figure data is selectively output from the switching circuit 57, and the figure color generating circuit 62 from the switching circuits 58 and 59.
The desired two kinds of color pixel data that define the figure color are selected and output. Here, the graphic color generation circuit 62
Is a predetermined two kinds of color pixel data (wide band color pixel data) based on the color pixel data arranged in the fifth and sixth words shown by 7 and 8 in FIG. 1 in the reproduction header signal by the header detection circuit 45. And narrow band color pixel data) are generated and output. The graphic color generation circuit 62 is configured to output only two types of color pixel data having a predetermined value (for example, a value indicating the midpoint gradation of the two types of reproduction color pixel data) regardless of the header signal. May be.

On the other hand, when the reproduced figure data has a value smaller than 8 gradations, it is determined that there is no figure data, and the switching circuits 57, 58 and 59 output the muting circuits 53, 54 and 55.
The three types of pixel data relating to the background color of the background color generation circuit 56 are selectively output and supplied to the DA converters 63, 64 and 65. Therefore, the DA converters 63, 64, and 65 are supplied with the pixel data relating to the figure and the pixel data relating to the background color in a time division multiplexed manner, and the subsequent signal processing is the same as when reproducing the pixel data relating to the natural image. The reproduction luminance signal relating to the graphic image or the background color is taken out to the output terminal 69, and the reproduction color signal relating to the graphic image or the background color is taken out to the output terminals 70 and 71, respectively. Accordingly, the display device displays the graphic image of the desired single hue on the background color of the desired single hue in such a manner as to be superimposed.

If the graphic data is reproduced while the pixel data of the natural image is being read from the image memories 46, 47 and 48, the graphic image based on the reproduced graphic data is superimposed on the natural image based on the header signal. It will be displayed in the following manner.

The digital audio signal branched and taken out by the decoding / error correction circuit 42 is digital-analog converted by the DA converter 72 and then output to the output terminal 73 as a reproduced audio signal.

The present invention is not limited to the above-mentioned embodiment, and for example, a magnetic tape recorded by the VTR 26 shown in FIG. 5 can be reproduced together with an analog audio signal, and the recording medium is a disk. It is not limited to.

EFFECTS OF THE INVENTION As described above, according to the present invention, it is possible to record and reproduce a high-definition color still image or a partial moving image together with an audio signal information signal, and record a high-definition image signal without band compression. Since the reproduction is performed, the recording / reproduction system can be constructed at a low cost, and the high-definition image signal for a single-color graphic can be converted into pixel data having a quantization bit number smaller than that of color high-definition image data. Since it is converted into the image data and recorded and reproduced, it is possible to reproduce a single-hue graphic image in a shorter time than a color high-definition image. When the cue playback is performed, the pixel data for the above figure is recorded immediately before, so that the non-display period from the cue to the time when the high definition image is displayed Can be shortened, and moreover, the graphic image can be displayed with high definition from the time of cueing until the color high-definition image is displayed. By arbitrarily inserting and recording the pixel data relating to the figure, it is possible to perform various reproductions.

[Brief description of drawings]

1 and 2 are diagrams showing an embodiment of a signal format of a digital video signal to be recorded / reproduced in the present invention, and FIG. 3 is a conceptual diagram showing an example of correspondence with an image of the digital video signal, FIG. 4 is a block system diagram showing an embodiment of an image acquisition device, FIG. 5 is a block system diagram showing an embodiment of an image formatting unit, and FIG. 6 is a block system showing an example of a main part of a disc recording system. Figure, 7th
FIG. 8 is a diagram showing an example of a signal format of one block of a digital signal recorded on a disc, and FIG. 8 is a block system diagram showing an embodiment of a reproducing apparatus of the present invention. 1 ... Header signal, 2 ... Pixel data part, 28 ... Digital video signal input terminal, 29 ... Digital audio signal input terminal, 30 ... Format conversion circuit, 32 ...
FM modulator, 40 ...... Playback signal input terminal, 43 …… High-definition decoder, 45 …… Header detection circuit, 46 to 48 …… Image memory, 49 …… Graphic memory, 50 …… Write address generator, 51 …… Read address generator, 52 …… Synchronous signal generator (SSG), 53 to 55,60 …… Muting circuit, 56
...... Background color generation circuit, 61 …… Figure data detection circuit, 62 ・ ・ ・
… Figure color generation circuit, 63 to 65,72 DA converter, 66 …… Playback luminance signal output terminal, 70,71 …… Playback color signal output terminal.

Front page continuation (72) Inventor Tetsuzo Shimada 2-2-1 Jinnan, Shibuya-ku, Tokyo Inside the Japan Broadcasting Corporation Broadcasting Center (56) References JP-A-58-196794 (JP, A) JP-A-58- 151791 (JP, A)

Claims (2)

[Claims] 1. A method for recording / reproducing a digital video signal, wherein a header signal of a plurality of words for defining a reproduction condition is time-division multiplexed on a pixel data group obtained by digital pulse modulating an analog video signal. The header signal has a fixed pattern synchronization signal in the first word, a first code indicating whether or not the pixel data transmitted subsequently to the header signal in a subsequent word relates to a high-precision image, and the pixel data is usually Second code indicating a color image or a monochromatic image and color pixel data designating the color of the monochromatic image itself or the background color thereof and recorded on a recording medium. When the analog video signal relates to the color image, the recording medium is used as a component encoded signal of a first luminance pixel data group and two types of color pixel data groups. When the analog video signal is related to the monochrome image, it is recorded in the recording medium as a second luminance pixel data group, and when reproduced, the header signal in the digital video signal reproduced from the recording medium. On the basis of the sync signal, write reproduction pixel data to a memory designated based on the first and second codes of the detected header signal, and read the accumulated pixel data from the memory to obtain an analog signal. A method for recording / reproducing a digital video signal, characterized in that it is configured to be displayed after being converted into. 2. A fixed pattern synchronization signal in the first word,
A first code indicating whether or not the pixel data transmitted subsequent to the subsequent word relates to a high definition image; a second code indicating whether the pixel data is a normal color image to a monochrome image; A header signal constituted by including at least the color of the monochrome image itself or color pixel data designating the background color of the monochrome image is a pixel data group of the component coding method obtained by digital pulse modulation of an analog video signal or a monochrome image. A reproducing means for reproducing the digital video signal from a recording medium in which the time-division multiplexed digital video signal is recorded in the pixel data group, and the header signal in the reproduced digital video signal extracted by the reproducing means. Header signal detection means for detecting based on a synchronization signal and decoding the following first and second codes respectively, and the pixel data group An image memory and a graphic memory to be memorized, and the pixel data group relating to a high-definition color image following the header signal in the reproduced digital video signal is designated in the image memory based on the output signal of the header signal detecting means. A first writing means for writing to the designated address, and a first writing means for writing the pixel data of the monochrome image in the reproduced digital video signal into the graphic memory only when the pixel data is detected by the header signal detecting means as a monochrome image. The second writing means, the first reading means for reading the accumulated pixel data of the image memory, the accumulated pixel data of the graphic memory, and the pixel data based on the color pixel data in the header signal are time-division multiplexed. Second reading means for obtaining pixel data, and output pixel data of the first or second reading means into an analog signal And means for conversion,
A digital video signal reproducing apparatus comprising means for generating a reproduced video signal from the converted analog signal.