JPS62128695A - High-precision picture signal reproducing device - Google Patents

Abstract

PURPOSE:To reproduce a high-precision picture signal by providing a D/A conversion to obtain a luminance signal and the first and the second chrominance signals by separately D/A-converting a luminance picture element data and the first and the second color picture element data. CONSTITUTION:The luminance signal and the first and the second chrominance signals are respectively synthesized in time series and taken out from a reproducing means, and are separately stored in three memories 7-9 by a memory means to be made simultaneous with each other. The three kinds of simultaneous picture element data that are read out in parallel are subjected to D/A- converting means 13-15 to be the luminance signal and the first and the second chrominance signals which constitute a reproduced high-precision picture signal. Since the luminance picture elements each other are stored and reproduced in the unit of one word while the color picture data of the same kind are in the unit of two words, even if an erroneous data that is not correctable occurs, the reproduction can be executed without letting the said data to be noticeable in the picture by means of the preceding-value holding. In such a way, the high-precision picture can be reproduced.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a high-definition image signal reproducing device, and particularly to a high-definition image signal reproducing device that has a wider band and a greater number of scanning lines than the current standard color television signal. The present invention relates to a device for reproducing image signals from a recording medium.

Conventional technology Compared to current color television systems (NTSC4, etc.), so-called high-definition television systems (hereinafter also referred to as high-definition systems), which can transmit images with much higher definition and higher quality, have been developed. It is being actively researched. This high-definition television signal (high-definition signal) has, for example, 1125 scanning lines, a field frequency of 60H2, and a luminance signal band of 20MHz, and the color signal has a wide band color signal of 7.0MHz and a narrow band of 5.5MHz7. Two types of color signals are transmitted. There are several prototypes for recording this high-definition signal, which is an analog signal, on a video disc, and as mentioned above, the high-definition signal has an extremely wide frequency band 5 to 6 times that of the current color television signal. Therefore, recording was performed after band compression was performed using techniques such as Nyquist sampling and frame correlation. Also,
When reproducing the video disc, the reproduced video signal is demodulated and then band expanded to obtain a reproduced high-definition signal.

Problems to be Solved by the Invention = 5- However, the circuit configuration for band compression and expansion described above has the problem of being extremely complicated and expensive. On the other hand, digital A-diodiscs may also record digital video signals containing color still images that play an auxiliary role to aid the imagination of listeners who listen to the playback of digital audio signals. Conventionally, there has been no digital audio disc playback device that plays back a digital video signal obtained by digital pulse modulation (PCM, etc.) of the high-definition signal together with an audio signal.

Therefore, the present invention has been developed by using a recording medium in which each pixel data obtained by separately sampling and quantizing the luminance signal and the first and second color signals constituting the high-definition IlO image signal is sequentially recorded. It is an object of the present invention to provide a high-definition image signal reproducing device which solves the above problems by reproducing the signal 8.

Means for Solving the Problems The high-definition image signal reproducing device according to the present invention separately samples the luminance signal and the first and second color signals constituting the high-definition image signal, and then separately performs quantum processing. a plurality of word pixel data portions in which luminance pixel data and first and second color pixel data each having a number of hanging bits m-pill (where m is an integer of 2 or more) and first and second color pixel data are sequentially arranged; , reproducing means for reproducing a digital signal from a recording medium on which a digital signal having a signal format consisting of a header signal of a plurality of words synthesized in chronological order at the beginning position of a pixel data portion is recorded;
a detection circuit for detecting a header signal from a reproduced digital signal; a memory means for distributing and storing the luminance pixel data and first and second color pixel data respectively in three memories; DΔ conversion means separately performs DA conversion on the three types of pixel data read out to obtain the luminance signal and first and second color signals.

Further, feature L' [The high-definition image signal reproducing device according to claim 2 specifies the reproduction conditions of each pixel data in the high-definition image signal reproducing device according to claim 1, and furthermore, This configuration includes an additional correction circuit that performs a value hold operation.

Effect: The luminance signal and the first and second color signals are synthesized in time series and taken out from the reproduction means, so that they are separately stored in three memories and synchronized by the memory means. The above three types of pixel data, which have been synchronized and read out in parallel, pass through the DA conversion means to become a luminance signal and first and second color signals, and these signals constitute a reproduced high-definition image signal.

Also, since luminance pixel data is recorded and reproduced in units of one word, and color image data of the same type is recorded and reproduced in units of two words,
Even if erroneous data that cannot be corrected occurs, it is possible to reproduce it without making it noticeable on the image by holding the previous value.

Embodiment FIG. 1 shows a block system diagram of an embodiment of the apparatus of the present invention. In the figure, an FM digital signal reproduced from a digital audio disc (not shown) is input to an input terminal 1. First, the recorded digital signals of this digital audio disc will be explained. FIG. 3 shows an example of the main part of the recorded digital signal of Shintanno A-Matsu 1.
~ is shown.

As shown in the figure, the header signal 31 consists of 6 words, and 1 word has 16 bits. Each word is transmitted in bit order from most significant bit (MSB) to least significant bit, and the header signal 31 is transmitted from the first word to
It is transmitted sequentially in the direction of the sixth word. header signal 31
is a signal format as described below, and the pixel data part (image data part) of one vertical line segment or one horizontal line segment that follows it.
The conditions for transmitting and reproducing images according to X.32 are defined. As shown in FIG. 3, the pixel data section 32 is a signal format A-mat in which pixel data with a quantization bit count of 8 bits are arranged two per word.

Here, as described above, the high-definition image signal (high-definition signal) includes a luminance signal in the band 20Ml-IZ,
Band 7.0M1 (Z wideband color signal and band 5.5MH
2 narrowband color signals, of which the luminance signal is the first one.
After the specimen dies, it is quantized at a sampling frequency t's to form a luminance pixel data group with a quantization bit count of 8 bits. Furthermore, the broadband color signal and the narrowband color signal each have a frequency f s / 2
The pixel data is sampled separately at a second sampling frequency and then quantized separately to form first and second color pixel data groups with a quantization bit count of 8 bits. In FIG. 3, Y, Y, Y2. ... is the above luminance pixel data, , C(xo, Co1.Co2.
. . is the above first color pixel data, and Cβo, Cβ1°C, . . . are the above second color pixel data.

β2 That is, as shown in FIG. 3, luminance pixel data is placed in the upper 8 bits of each word, first or second color pixel data is placed in the lower 8 bits of each word,
Moreover, the first and second color pixel data are arranged alternately for each word.

FIG. 4 shows an example of the signal format of the main part of the digital signal. While FIG. 3 shows a signal format when transmitting a digital signal through a one-channel transmission path, FIG. 4 shows a signal format when transmitting a digital signal through a two-channel transmission path.

FIG. 5 shows an example of the signal format of a digital video signal. Immediately after the header signal 31, the pixel data portion 32 of formats 1 to 1 as shown in FIG. This header signal 31 and the pixel data section 32 are synthesized in block units in time series.

FIG. 6 shows a block system diagram of an example of the essential parts of a disk recording system. In the figure, a digital video signal having a signal format as shown in FIG. Digital audio signals reproduced from the master tape come in in synchronization with the digital video signals, and these input signals are supplied to the format conversion circuit 36. The format conversion circuit 36 generates and outputs a digital signal synthesized in block units in time series in the signal format shown in FIG. 7, which is known for digital audio discs.

Here, in one block of signals shown in FIG. 7, S indicates the arrangement position of an 8-bit fixed pattern synchronization signal indicating the start of the block. Ch-1゜Ch-2, Ch-3
and Ch-4 are one of the 16-bit digital signals (i.e., the digital audio signal and the digital video signal) of each channel among the four channels.
Indicates the location of the word.

Further, P and Q shown in FIG. 7 are each 16-bit error correction codes. Furthermore, CRC is a 23-bit error detection code.
ch −i ~ Ch−/1 arranged in the same block
．． ．． P, Q (7) Each word, for example, ×230X5 +X
2 obtained when dividing by the generator polynomial 4 +X+1
This is a 3-bit remainder, and during playback, the signal from the 9th bit to the 127th bit of the same block is divided by the above generator polynomial, and if the resulting remainder is 0, it is detected as having no error. used for Furthermore, the seventh
In the figure, Adr indicates the multiplexing position of one bit of each second control signal (address signal) used for random access and the like. This control signal distributes each bit data and transmits one bit in one block. For example, all bits of the control signal are transmitted by 196 blocks (that is, the control signal is composed of 196 pits).

Furthermore, U is a spare 2-bit I~ called a user's bit 1~, which transmits a language to be used in an interactive operation by connecting a combicoater to a playback device, for example. Then, ff from S to U shown in FIG.
t'l 30 hits constitute one block of signal,
The digital signal is 44.1 KH2 in this block unit.
are synthesized at frequencies and transmitted in chronological order. 1 above
The 96-bit control signal has a configuration in which four types of address codes of 49 bits each are synthesized in chronological order.
All types of address codes have a similar signal format.

In this way, among the signal transmission paths of a total of four channels, Ch-1 to Ch-4, for example, the digital audio signal has a sampling frequency of 44.1 KH2, an fH conversion bit number of 16 bits, and ch-i and Ch-4. The header signal 31 and the pixel data section 32 are arranged in two words shown as Ch-3-13= and Ch-4 and transmitted sequentially.

The digital signal extracted from the format conversion circuit 36 in block units in the signal format as shown in FIG.
The signal is supplied to the RZ modulator 37, where the signal excluding the 8-bit synchronization signal is subjected to scrambled NRZ modulation by modulo-2 addition with a signal from a preset random number table (for example, an M-sequence code). After the FM modulator 38
supplied to The frequency-modulated digital signal taken out from the FM modulator 38 is supplied to a known cutting machine via an output terminal 39, where it is converted into a modulated light beam and then focused and irradiated onto the photosensitive agent on the disc-shaped recording master. Ru.

A large number of disks (digital audio disks) can be reproduced by passing this disc-shaped recording master through a known developing process and a manufacturing machine.

The FM signal reproduced from such a digital audio disc is input to the input terminal 1-1/I shown in FIG.
- is supplied to the FM demodulation circuit 2 through FM demodulation there, and then supplied to the decoding/error correction circuit 3 where descrambling, decoding and error correction are performed to reproduce the signal format shown in FIG. It becomes a digital signal. This reproduced digital signal is supplied to a distributor 5 and a header detection circuit 6 in the high-definition decoder 4, respectively. The distributor 5 supplies the luminance pixel data of the upper 8 bits of each word of the pixel data section 32 to the memory 7, and the color pixel data of the lower 8 bits of each word is distributed to the memories 8 and 9 alternately for each word. supply Accordingly, memory 7 is supplied with luminance pixel data, memory 8 is supplied with first color pixel data, and memory 9 is supplied with second color pixel data.

On the other hand, the header detection circuit 6 detects the header signal by detecting the fixed pattern synchronization signal of the first word of the header signal 31, decodes the identification code in the subsequent five words, and also detects the screen address signal. These signals are then supplied to the write address generator 10, which controls the output write address to write each pixel data to the specified address of the specified memory. A read address generator 11 generates a read address based on a signal from a synchronization signal generator (SSG) 12, and supplies it to the memories 7.8 and 9, respectively, thereby separately inputting the read address to the memories 7.8 and 9. The three types of accumulated pixel data are read out simultaneously and 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 changed to 4, for example.
8.6MHz (-576x2x (5/4)
In the case of the first and second color pixel data, the sampling frequency is read out at a sampling frequency of 24.3 MHz. Pixel data is read out in the order of horizontal scanning of the screen.

The three types of pixel data read out simultaneously and in parallel from memories 7.8 and 9 are sent to DA converters 13, 14 and 1.
5 and is DA-converted there to become an analog signal. The reproduced luminance signal taken out from the DA converter 13 is supplied to the synchronization signal addition circuit 16, where the 5SG1
After the synchronization signal from No. 2 is added, the signal is output to the output terminal 19. In addition, the first . The second color signals (wideband color signal and narrowband color signal) are added with a synchronizing signal in the synchronizing signal adding circuits 17 and 18, and then outputted to the output terminals 20 and 21. These output signals become the high-definition image signal (high-definition signal) by passing through a decoder (not shown).

The digital audio signal branched and extracted by the decoding/error correction circuit 3 is subjected to digital-to-analog conversion by the DA converter 22 and then outputted to the output terminal 23 as a reproduced audio signal.

Here, in the decoding/error correction circuit 3, correct pixel data is output as is, and pixel data with errors is normally restored to correct pixel data using an error correction code, but there may be cases where restoration is not possible. In consideration of such a case, in the present embodiment, a correction circuit as shown in FIG. 2 is provided before the memories 7 to 9. In the figure, input terminal 24
The pixel data that has entered is stored in the data holding circuit 27
While being held for a word period, it is supplied to the terminal 28a of the data selector 28. Data selector 28 is input terminal 2
When the error is corrected (and when the error is not corrected because the data is correct) by a control signal that has a different logic value depending on whether or not the error was corrected, which comes in through 5.
selects and outputs, for example, reproduced luminance pixel data from the input terminal 24 as is, and if error correction is not possible, selects the previous luminance pixel data supplied from the data holding circuit 27 to the terminal 28b to the output terminal 29. Output. In the case of color pixel data, as shown in FIGS. 3 and 4, the data is replaced with color pixel data two words earlier.

Therefore, if the pixel data Y, C (xl is incorrect and cannot be corrected, then Y2.C (Y instead of xl.
C (xo is replaced. Similarly, pixel data Y3.Cβ1
Yl if not corrected.

Cβ0 is replaced. In this case, as shown in Figure 4, 1
When a digital video signal is transmitted using a 2-channel channel during a block, the pixel data that is converted into uncorrected pixel data is r4 degree pixel data.

Since both the first and second color pixel data are pixel data from one block transmission period ago, previous value bolding can be performed naturally.

Note that the recording medium to be reproduced may be a recording medium other than a digital audio disc.

Effects of the Invention As described above, according to the present invention, high-definition image signals can be reproduced from a recording medium, and color still images and partial moving images with higher image quality than before can be reproduced. In addition, since three types of pixel data are reproduced using the component encoding method, even in current television systems, high viscosity 1 degree images can be reproduced by thinning out sample points around the screen. It is possible to obtain higher-definition images than those reproduced from conventional digital audio discs, and when two words of pixel data are transmitted in one block, J is used to hold the previous value.
: It has many features such as the ability to naturally perform the correction operation of the correction circuit.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the device of the present invention;
FIG. 2 is a block system diagram showing the main part of another embodiment of the device of the present invention, FIGS. 3 to 5 are diagrams showing an example of the signal format of the main part of the digital signal to be reproduced, and FIG. The figure shows an example of the essential parts of a digital audio disc recording system, and FIG. 7 shows an example of the signal format of one block of a digital signal to be reproduced. DESCRIPTION OF SYMBOLS 1... Reproduction FM signal input terminal, 3... Later, error correction circuit, 4... High-definition decoder, 5... Distributor, 6... Header detection circuit, 7-9... Memory ,
10...Write address generator, 11...Read address generator, 12...Synchronization signal generator (SSG)
), 13-15.22...DA converter, 16-18.
...Synchronization signal addition circuit, 19...Reproduction luminance signal output terminal, 20.21...Reproduction color signal output terminal, 23...
Reproduction audio signal output terminal, 2/I...Reproduction pixel data input terminal, 27...Data holding circuit, 28...Data selector, 29...Reproduction pixel data output terminal.

Claims (2)

[Claims] (1) After separately sampling the luminance signal and the first and second color signals that constitute a high-definition image signal that has a wider band and more scanning lines than the current standard color television signal. Luminance pixel data each having a number of quantization bits m (however, m is an integer of 2 or more) that has been quantized separately, and the first and second
A pixel data section of multiple words (however, 1 word is 2 m bits) in which color pixel data of 2000 and 2000 are sequentially arranged, and an image of the pixel data section that is synthesized in chronological order at the beginning position of the pixel data section. a reproduction means for reproducing the digital signal from a recording medium on which a digital signal having a signal format consisting of a header signal of a plurality of words defining transmission and reproduction conditions for the reproduction means; and a reproduction means for reproducing the header signal from the output reproduction digital signal of the reproduction means. a detection circuit for detecting, and a memory means for distributing the luminance pixel data and first and second color pixel data in the reproduced digital signal based on the header signal from the detection circuit and separately supplying the data to three memories. The luminance pixel data and the first and second color pixel data, which have been synchronized and read out in parallel, from the memory are separately DA-converted to convert the luminance signal into the first and second color pixel data.
1. A high-definition image signal reproducing device comprising: DA conversion means for obtaining a color signal. (2) Among the luminance signal and first and second color signals that constitute a high-definition image signal that has a wider band and a greater number of scanning lines than the current standard color television signal, the luminance signal is The number of quantization bits obtained by sampling and quantizing at the first sampling frequency m bits (however, m is an integer of 2 or more)
The luminance pixel data of 2 m bits per word is arranged in the first half or the second half m bits of each word, and the first and second color signals are transmitted at a frequency 1/2 times the first sampling frequency. The first and second m bits of quantization bits obtained by separately sampling at a certain second sampling frequency and then quantizing separately.
one of the color pixel data is placed in the remaining m bits in each word where the luminance pixel data is not placed,
and a pixel data section of a plurality of words in which the first and second color pixel data are alternately arranged word by word, and the pixel data section that is synthesized in time series at the beginning position of the pixel data section. a reproduction means for reproducing the digital signal from a recording medium on which a digital signal having a signal format including a header signal of a plurality of words defining image transmission/reproduction conditions, and a reproduction means for reproducing the digital signal from the output reproduction digital signal of the reproduction means; a detection circuit for detecting a header signal; and when error correction of the luminance pixel data and the first and second color pixel data is completed in the reproduced digital signal from the reproduction means, outputting the pixel data as is; If any of the above pixel data cannot be corrected,
Among the two pixel data of the same word containing the pixel data that could not be error corrected, the luminance pixel data is replaced with the luminance pixel data of one word before, and the first or second color pixel data is replaced with the two words of pixel data. a correction circuit that replaces the previous first or second color pixel data; and a correction circuit that distributes the luminance pixel data from the correction circuit and the first and second color pixel data based on a header signal from the detection circuit. a memory means for separately supplying three memories; and a first and a second luminance pixel data that are simultaneously read out from the memories in parallel;
1. A high-definition pixel signal reproducing device comprising DA conversion means for obtaining the luminance signal and the first and second color signals by separately DA converting the color pixel data.