JPH01256292A - Color television signal storage reproduction system - Google Patents

Abstract

PURPOSE:To reduce deterioration in picture quality storing a still picture of an NTSC color television signal efficiently by 2 frames (1 color frame) without modifying a composite signal and storing a synchronizing signal part without increasing the capacity of a main memory. CONSTITUTION:One color frame (2 frames) of an NTSC color television signal is used as the recording unit and the composite signal is converted directly into a digital and stored. Then nine lines of the vertical synchronizing signal part and a 1st 2-line are stored all and only the effective period of the video signal is stored respectively. In case of reproduction, the 9 lines of a 1st field vertical synchronizing signal and the succeeding 2-line are read consecutively, the signal by 2-line is stored in line memories 20, 21 separately from the main memory 19, the horizontal synchronizing signal part is read alternately from the line memories 20, 21 and the video signal is read out of the main memory 19 to obtain a consecutive composite video signal. Thus, deterioration in the picture quality is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a color television signal storage/reproduction method for efficiently storing and reproducing NTSC color television signals.

[Summary of the invention]

Converts color television signals to digital signals,
If you want to use the memory effectively when storing it in memory, directly or once transmitting and recording it to a recording medium such as a magnetic disk, then reproducing it, transmitting it and storing it in memory, and then reproducing it (reading it out), , Ii! ! 1. Deterioration of quality, high cost,
Difficulties in processing were unavoidable.

The present invention is based on a single color frame of NTSC color composite signal. It is directly converted into a digital signal as a unit and stored in a memory (main memory). At that time, all nine lines and the first two lines of the 1-hand synchronization signal part are stored, and the video signal is stored only during the valid period. Also, line memory 2
At the time of playback (reading), the above two lines are stored in this line memory, the horizontal synchronization signal part is read out alternately from the line memory, and the vertical synchronization signal 1 read out from the main memory.
The next two lines and the effective video signal are combined to obtain a continuous color composite signal.

As a result, it is possible to provide a color television signal storage and playback method that causes less deterioration in image quality without increasing costs and that facilitates post-processing. [Prior art] Color television signals are converted into digital signals. In cases where the data is temporarily stored in a memory, either directly or once read out, transferred and recorded on a recording medium such as a magnetic disk, and then reproduced, transferred to the memory, stored, and repeatedly read out to be displayed as a still image.

In order to effectively utilize the memory, only the video signal period excluding the synchronization signal (horizontal synchronization signal or color burst signal) is often stored. However, in a composite signal, the color burst signal becomes the color reference for the video signal section, so if the color burst information is not stored in the memory, color management of the output signal becomes impossible. Such a problem becomes a problem when the recording and reproducing conditions are different, or when the recording device and the reproducing device are different.

As a method to remove such defects.

- For example, there is a method in which the color signal is decoded and then digitized and stored. FIG. 3 shows an example of a telecode television signal storage system, in which a color television signal a is decomposed by a decoder 1 into a Y signal, an RY signal part, and a BY signal part. Each signal is A
The signals are digitized by D converters 2-4 and stored in memories 5-7. The lock signal and memory timing required for AD conversion are separated from the color television signal a by a synchronization signal separator 8, and - synchronization signals (horizontal synchronization signals,
It is generated using a color burst signal) e. In the case of an NTSC color television signal, the write clock generator 9 generates a write clock f of 4·fsc (fsc: the same wave number as the color subcarrier) and supplies it to the AD converters (AD) 2 to 4 and the memory controller 10. On the other hand, Memo IJ (M
EM) Data 5 to 7 are directly read out or once read out (not shown), transferred and recorded to an external recording device such as a VTR, magnetic disk device, optical disk device, etc., and reproduced as needed to be stored in memories 5 to 7. 7 and then read out from the reference signal g in synchronization with the read clock h generated by the synchronization signal generator 11, and then sent to the DA converter (DA).
12 to 14 are analog Y signal sections.

The signal is converted into an RY signal part and a B-Y signal part, and further modulated into a video signal m by an encoder 15. At this time, the encoder 15 reproduces the color by modulating the color subcarrier in the same phase as the color burst signal of the output synchronization signal l. The video signal m is further added with a composite synchronizing signal l including a color burst signal by an adder 16 to become a color television signal a.

To mention the memory capacity here, the Y signal is 4
- Sampling is performed with fsc, but since the bandwidth is narrow for the R-Y and B-Y signals, 2 fsc is sufficient. For this reason,
To store one still image, a total of 2 frames (1 frame for Y signal, 1/2 frame each for R-Y, B-Y signals)
frame) is required.

Although not described here, there is also a method in which the NTSC color television signal is digitized as a composite signal and separated into Y, R-Y, and B-Y signals using a digital filter. In this case, only one AD converter is required.

[Problem that the invention seeks to solve]

The above-mentioned conventional technology requires a decoder and an encoder when recording and reproducing a composite signal, which not only causes significant image quality deterioration especially in the process of separating luminance and chromaticity, but also requires three AD converters and DA converters. It requires a system and has the disadvantage of high cost.

Furthermore, it is necessary to add a composite synchronization signal including a color burst signal to the encoder output, which poses difficulties in post-processing.

The present invention solves these shortcomings, stores color phase information with only the addition of a small amount of memory without increasing the cost of main memory, and performs preprocessing (separation of luminance and chromaticity, decoding, etc.), The object of the present invention is to provide a color television signal storage/reproduction method that greatly simplifies post-processing (encoding, etc.) and reduces image quality deterioration.

[Means for solving mirror points]

In order to achieve the above object, the present invention is constructed as follows. That is, one color frame (two frames) of an NTSC color television signal is used as a recording unit, and the composite signal is directly converted into a digital signal and stored. and.

The data to be stored in memory is as follows.

■Vertical synchronization signal section All 9 lines are stored.

■The first two lines (line number/%10°71611 shown in FIG. 2) are also completely memorized.

■Video signals are stored only during their valid period.

When data of 9 or more is to be reproduced, the 9 lines of the vertical synchronizing signal of the first field and the following 2 lines are read out consecutively, but each of the 2 lines is stored in a line memory separate from the main memory. Thereafter, the horizontal synchronizing signal section is read out alternately from the line memory, and the video signal is read out from the main memory, thereby obtaining a continuous composite video signal.

[Effect]

As a result, composite signals can be efficiently stored in the memory (without increasing the number of memory elements), so compared to the prior art, the data in the memory and other memory media ( It is also possible to save time when transferring data to a magnetic disk, optical disk, etc.
Since a composite video signal can be obtained immediately after conversion, post-processing becomes easy and the cost of the system can be reduced.

〔Example〕

Before explaining the embodiments, the concept of the present invention will be explained first.

As mentioned earlier, when converting to a digital signal such as a color television signal and storing it in a storage element, in order to use the storage element economically, the entire composite video signal is not stored, but rather during the horizontal blanking period. In many cases, only the so-called effective video signals excluding the signals (including horizontal synchronization signals and color burst signals) are stored. On the other hand, in order to record and reproduce still images of NTSC color television signals without degrading the image quality, it is preferable to generate composite signals in units of one color frame (four fields).

In this case, the relationship between the amount of data and the amount of memory used is 1
When the color frame information is digitized into 8 bits at 4 fsc (fsc: color subcarrier frequency), it is approximately 955 bits.
．． 5 bytes (a byte is 8 bits); for example, if a 256 bit semiconductor memory is used, 32 are required. On the other hand, if only the effective video signal portion is digitized, the number of bytes becomes 741.888, and it can be configured with 24 identical semiconductor memories. However, if only the effective video signal portion is stored, the color phase of the output video signal cannot be specified.

This becomes a big problem, especially when digitally stored under different conditions where burst phase shifts occur.

Incidentally, in the color burst signal, which is the color standard of the NTSC color television signal, the phase is opposite to the axis for each line, and it can be considered that two lines are repeated as bare signals. Therefore, it is not necessary to store all the horizontal synchronization signals and color burst signals. Therefore, when writing one color frame of video data to the main memory, only the first two lines take in all the data (910 data x 2 in the case of 4fsc), and the subsequent video signals only have a valid period (4 fsc).
fsc, each line (768 data) is stored.

When reading out this video data, the first two lines are each taken into a line memory separate from the main memory, and 142 data (horizontal blanking period = horizontal synchronization signal and color burst signal) are read out alternately, while the remaining 7 lines are read out.
A series of data can be obtained by reading the 68 data from the main memory.

Therefore, when this data is restored to an analog signal by a DA converter, an NTSC signal with matching color phases can be obtained. In this case, the increased memory capacity is 284
Of course, since one piece of data is 0.04% of the total, there is no need to increase the number of semiconductor memories.

Furthermore, by storing the vertical synchronization signal part (9 lines) of each field, the entire input composite synchronization signal is equivalently stored, and by DA converting a series of digital data, a complete NTSC signal can be reproduced. This eliminates the need for the conventional post-DA conversion process (addition of composite synchronization signals and color burst signals), resulting in significant circuit simplification. Moreover, even if the vertical synchronization signal part for 4 fields is stored, the required capacity is about 775 bytes, an increase of about 4%, and it is 786 bytes when configured with 24 semiconductor memories (ICs) with 256 and pits. Since it is within a byte, it does not affect the increase in ICs.

2. As a result, it becomes possible to efficiently store television signals without increasing the number of semiconductor memories.

An embodiment of the present invention will be described below with reference to FIG. 1 in the case of an NTSC color television signal. 17 is A
D converter, which converts NTSC color television signals (for example, resolution 8 bits), 14.3 MHz
18 is a write clock generator whose phase is locked to the color burst signal of the input video signal.
Generates a 4.3MHz clock signal. Reference numeral 19 is a main memory capable of storing video signals for two frames. 78
It has a capacity of 6 bytes. 20.21 each has a capacity of 910 bytes in one line memory. 2
A memory controller 2 outputs write/read signals and other control signals to the main memory 19 and the one-line memory 1J20.21. 23 is a read clock generator;
Generates a 14.3MHz read clock signal. 24
converts digital data into an analog signal using a DA converter.

This operation will be explained below. NTSC color television signal a' is applied to AD converter 17 and write clock generator 18. N in AD converter 17
The TSC signal a' is converted into digital data n in synchronization with the write clock f and is supplied to the main memory 19. Writing data to the main memory 19 and reading data from the main memory 19 are performed using R/W from the memory controller 22.
This is done in accordance with the control signal p. Memory controller 2
The timing of the control signal outputted from 2 will be explained with reference to FIG. A1 and A2 in FIG. 2 are the 1.3rd field and 2.4th field of the NTSC color television signal.
Indicates the vertical sync signal part of the field and its vicinity. All the signals are shown at active low level, meaning that data n is written into the main memory 1719 during the low level period of the main memory R/W signal, for example.

Data is written to the main memory 19 from the first line to the 11th line of the first field.

Further, lines from the 12th line to the 21st line are not written because they are in the vertical blanking period. Further, from the 22nd line where the effective video signal period begins, writing is performed except for the period in which the horizontal synchronizing signal and color burst signal are present.

To explain more specifically, when sampling with one line of 4 fsc, 910 samples of data are obtained. Of these, 768 samples are valid video signals.

142 samples are allocated as a horizontal blanking period. In addition, write the vertical synchronization signal section.

Only the first field has 11 lines, but the remaining
There are nine lines from the field to the fourth field.

(In FIG. 2, the write pulse of the third field is indicated by a broken line.) On the other hand, reading from the main memory 19 is performed based on the read clock h generated by the read clock generator 23. The timing of reading from the main memory 19 is
This is as shown in the main memory R/W signal p, which is the same as that at the time of writing. Data q read from main memory 19 is applied to the X terminal of data switch SW1 and 1-line memories 20 and 21. This one line memory is 9, for example 9
FIF of 10 words (one word is 8 bits 0)
O (first-in-first-out) type memory is preferred. In such a memory, 910 words can be written while adding 4 fsc clocks.

After that, by switching to read mode, one line of data 91
0 words can be read repeatedly. Therefore, by adding a W (write) signal to the 1-line memory 2o and a W signal part to the 1-line memory 21 as shown in FIG. is the first
One line is written. After that, R to 1 line memory 20.
(Read) signal By adding the R signal S' to the 1-line memory 21, the 10th line becomes the 12th line.
The first line is read out alternately on the 13th line.

The output of the 1-line memory 20 is the X terminal of the data SW2, 1
Since the output of the line memory 21 is connected to the X terminal of the data SW2, the Z of the data SW2 can be changed by switching the data of the X terminal and the
A continuous signal is obtained from the 12th line to the 21st line at the terminal. Similar reading is performed in subsequent lines, but from the 22nd line, the output of data q and data SW2 from the main memory 19 is changed to SW+ by data SW1.
It is switched by the switching signal U. here.

The SWI switching signal U is the 22nd field of the 1.3th field.
After the line and after the 284th line of the 2.4th field, each line is a signal that selects the input of the X terminal for 768 clocks and the input of the Y terminal for 142 clocks. Note that the fields from the second field to the fourth field are switched as shown in FIG. Therefore, since continuous data over four fields is obtained from the two terminals of data SWI, the NTSC signal a' is obtained by converting it into an analog signal by the DA converter 24.

Although we have explained here the method of storing still images of NTSC color television signals in semiconductor memory and directly playing them back, it is also possible to transfer the stored contents from 19 parts of the main memory to a VTR, optical disk, or magnetic disk for recording. ,
If necessary, it is possible to reproduce the data and transfer and store it in the memory again, or to replace the main memory with a transmission path, making it possible to effectively utilize not only the memory but also the nine lines.

Also, is there a reference signal in the read clock generator 23? By adding this, it is also possible to obtain an NTSC signal a' phase-locked to the reference signal. Furthermore, here, F
Although the IFO format has been described as an example, it goes without saying that the same effect can be obtained by controlling the address using a memory element such as a RAM or CCD having a memory capacity of two lines.

〔Effect of the invention〕

According to the present invention, a still image of an NTSC color television signal can be efficiently converted into two frames (one frame) as a composite signal.
1 color frame), and the synchronization signal part can be stored without increasing the main memory capacity.
There is little deterioration in image quality (.

Moreover, it is possible to realize a television signal storage/reproduction device that is easy to post-process.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the present invention. FIG. 2 is a timing diagram of FIG. 1, and FIG. 3 is a block diagram showing an example of the conventional method. 17: AD converter, 19: main memory. 20.21 Niline memory, 22: Memory controller, 24: DA converter.

Claims (1)

[Claims] 1. Converting the NTSC color composite signal to a digital signal, then storing one color frame (four fields) of the effective video signal excluding the horizontal and vertical blanking periods in a storage element, and reproducing it. In this method, when storing an effective video signal portion in a storage element, in addition to the effective video signal, at least two consecutive lines of horizontal blanking period signals (including a horizontal synchronization signal and a color burst signal) are stored.
When reading from the storage element, before reading out the effective video signal of each line, one of the signals in the horizontal blanking period is read out in one line, and in the next line, one of the signals in the horizontal blanking period is read out. A color television signal storage device characterized in that a synchronizing signal section satisfies an interleaving relationship by alternately reading signals of two horizontal blanking periods, such as reading out the other signal of two lines. Playback method. 2. A color television signal storage/reproduction method according to claim 1, characterized in that a vertical synchronization signal portion is stored and reproduced.