JPH0722405B2 - Recording / playback method for still image signals - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a recording / reproducing system for still image signals, and particularly displays an incomplete image during a waiting time required for displaying an image during reproduction. The present invention relates to the recording / reproducing system of the still image signal.

[Outline of Invention]

For example, a still image signal composed of three primary color signals of a high-definition image with 1000 or more scanning lines recorded on a digital signal recording medium such as a magnetic disk or an optical disk is read out and transferred to an image memory to display a still image. It takes about 4 to 8 seconds.

Conventionally, since no signal is output from the device while the image signal is being transferred from the recording medium such as a disk to the image memory, a signalless waiting time of about 4 to 8 occurs.

According to the present invention, by displaying an image even if it is incomplete during the waiting time until a complete still image signal is displayed,
The purpose is to significantly reduce the no-signal period during which an effective image is not displayed.

The present invention provides an image memory of n blocks (n: integer of 2 or more) that can be controlled independently for each of the R, G, B primary color signal channels, and transfers (records) from the memory to a recording medium. At times, each primary color signal is sent to a different memory for each sample in the image memory of the n blocks and stored sequentially, and when reproduced from the recording medium and re-transferred to the image memory, at least one primary color signal is first stored. The signals of the pixel groups are transferred to at least one of the memory blocks of the three primary color signals and read out to display a monochrome image, and the signals of the remaining pixel groups are transferred from the recording medium to the predetermined memory blocks. It is intended to be transferred to.

According to the present invention, the first image displayed is monochrome, and the horizontal resolution is 1 / n, but the time until the image is displayed is until the complete still image is displayed. Since the time is reduced to 1 / 3n, it is possible to confirm the content in a short time and reduce the psychological burden on the operator.

[Conventional technology]

As a conventional still image recording / reproducing system, a still image signal is stored in a memory and then transferred and recorded on a digital signal recording medium such as a magnetic disk, and about 0.7 megabytes of data having a capacity of one screen is temporarily stored in the memory. , And no signal is output during the transfer period. Then, the image is displayed after the transfer is completed. Since the transfer speed of a magnetic disk is a 5-inch type and is usually about 1 megabyte / second, the waiting time required for displaying an image is about 1 second for one frame of an NTSC television signal. In this way, conventionally, the capacity of one screen is collectively transferred to the memory,
A still image is displayed after the transfer is completed. Therefore, the image signal is not output during the transfer to the memory.

[Problems to be solved by the invention]

In order to transfer a high-definition still image signal of about 4 megabytes from a digital signal recording medium such as a 5 inch type magnetic disk or a 5 inch optical disk to an image memory by applying the above-mentioned conventional technique, recording is performed. Since the transfer rate from the medium is about 1 megabyte to 0.5 megabyte per second, it takes about 4 to 8 seconds until the transfer of the image signal is completed. Conventionally, a normal signal is not output during image transfer, so this time is psychologically unfavorable to the operator.
Further, even if a signal different from the image signal intended by the operator is erroneously operated, it is not known until after 4 to 8 seconds have passed, so the operation efficiency is extremely poor.

The present invention solves these problems, and provides a still image signal recording / reproducing apparatus capable of significantly reducing the no-signal period until displaying an image signal as compared with the prior art without providing a plurality of digital signal storage media. The purpose is to do.

[Means for solving problems]

In order to achieve the above object, in the present invention, the capacity of one block for each of the R, G, and B primary color signal channels is 1 / n of the required total number of pixels of one primary color signal and can be controlled independently. Provide a memory of block (n is an integer of 2 or more),
It is characterized in that these memories are effectively controlled in transfer of signals from the memory to the recording medium, retransfer from the recording medium to the memory, and output.

The image signal to be transferred is composed of a pixel group in which each primary color signal is sequentially stored in the memory of the 1st to nth blocks for every n samples, and is transferred from the memory to the recording medium and from the recording medium to the memory. Retransfer is performed in units of these pixel groups.

The principle of the present invention will be described below for the case of n = 2.

First, when the R, G, B primary color signals are transferred to the recording medium, the first and second pixel groups separated for each primary color signal are stored in a memory provided with two blocks each, and then, for example, the first of the G signals is stored. , The contents of the second memories G ₁ and G ₂ are transferred to a recording medium, and then B
Contents of _first and second memories B ₁ and B ₂ of signals, first and second memories of R signals
The contents of the memories R ₁ and R ₂ are sequentially transferred to the recording medium.

Next, when the primary color signals transferred to the recording medium are retransferred to the memory for storage and output, each memory is controlled as shown in FIG. That is, the G ₁ to R ₂ of the waveform of Figure 2 represents the state of each memory G ₁ to R _2, the period of the low level is the memory in the storage (writing), part of the high-level This is a period during which the memory is repeatedly read. Note that t
₀ indicates the start of retransfer from the recording medium to the memory, and t ₆ indicates the end. Also, each adjacent period from t _{0 to} t ₆ is constant. GSW, BS
W and RSW represent the selected states of the outputs of the two sets of memories, G ₂ , B ₂ , R ₂ in the negative polarity part and the positive polarity part in the positive polarity part.
Outputs the memory contents of G ₁ , B ₁ , and R ₁ .

First, the first pixel group of the G signal is transferred to the G ₁ , G ₂ , B ₂ and R ₂ memories. No signal is output during this period 1 (between t _{0 and} t ₁ ). This is done by using the blanking switch. And after the transfer is completed, the G _2, B _2, R ₂ content of the memory of each primary color signals simultaneously output, and displays a monochrome signal comprising components of the G signal. Next, the first pixel group of B signals and R signals is sequentially transferred to the B ₁ and R ₁ memories of each original signal, and after completion, the contents of the G ₁ , B ₁ and R ₁ memories of each primary color signal are output simultaneously. Displays a color signal with a horizontal resolution of 1/2. A monochrome signal is displayed during a period 2 (between t _{1 and} t ₃ ) from the start to the end of the transfer to the B ₁ and R ₁ memories. Next, the second pixel group of each primary color signal is transferred to the G ₂ , B ₂ , and R ₂ memories that were outputting the monochrome signal, and after completion (after t ₆ ), 2 of each of the G, B, and R signals is output. Output the contents of the block's memory simultaneously and display the full color signal. G _2, B _2, R ₂ horizontal resolution period 3 to the end (the period of t ₃ ~t ₆₎ from the transfer initiation to the memory to display the color signal of 1/2.

FIG. 3 shows the pixel structure of G, B, R signals on the m-th scanning line of the monitor at the time of monochrome signal. G signal is 1
Two sets are assigned to each signal for each pixel.

FIG. 4 shows the pixel structure of G, B, R signals on the m-th scanning line of the monitor when the color signal has a horizontal resolution of 1/2. Two sets of G, B, and R signals are assigned to every other pixel.

It should be noted that switching from a color signal with a horizontal resolution of 1/2 to a complete color signal may be performed sequentially at the end of each transfer of the G ₂ , B ₂ , and R ₂ memories. further,
Switching between monochrome signals, color signals with horizontal resolution of 1/2, and complete color signals is performed within the vertical blanking period to prevent image drooling during switching. The transfer of the image signal to the memory is asynchronous with the image display cycle.
Therefore, image drooling occurs at the time of switching. Therefore, each memory is switched by a signal obtained by retiming the GSW, BSW, and RSW signals shown in FIG. 2 with the VD signal (vertical drive signal). Here, the switching phase of GSW is ahead of BSW and RSW because GSW retiming with VD signal is the same phase.
Switching enters the write period of G2 memory, because the period the contents of the asynchronous G ₂ memory image display is output screen to prevent this since disturbed.

[Action]

As a result, the no-signal time required to display a still image is, for example, G when two blocks of memory are provided for each primary color signal.
The time required to transfer the first pixel group of the G signal to the first and second memories of signals, the second memory of B signals, and the R signals is shortened to about 1/6 compared to the waiting time of the conventional method. can do. Generally, when n blocks of memory are provided for each primary color signal, the above time can be shortened to 1 / 3n.

〔Example〕

 An embodiment of the present invention will be described below with reference to FIG.

First, recording of a still image signal will be described. Terminals 4,5,6
The analog high-definition three-primary-color signals G signal, B signal, and R signal given to the above are converted into digital signals by A / D converters 7, 8, and 9 and supplied to the switches 10, 11, 12. Next, the control circuit 22 controls the switches 10, 11 and 12 so as to select the output of the A / D converter. The digitally encoded signals are alternately fetched into the first memories 13, 15, 17 and the second memories 14, 16, 18 every other pixel, and the data rate is reduced to 1/2 in each memory to reduce the memory operating margin. To take. This capture is a control circuit
One frame period of the input image signal is instantaneously taken into the memory by the frame pulse signal generated in 22. Next, the control circuit 22 controls the outputs of the memories and the switches 19, 20, 21 to control the G signal first memory 13, the second memory 14, the B signal first memory 15, the second memory 16, and the R signal. The image signals are transferred to the optical disc 29 in the order of the first memory 17 and the second memory 18, and the recording of the image signals is completed.

Next, reading out of the recorded image signal and image display will be described. The control circuit 22 switches the switches 10, 11 and 12 to select the output of the optical disk 29, and the order of the output signals of the optical disk 29, the first memory 13, 15, 17, and the second memory 14, 16, 18 are set according to the present invention. The display is controlled according to the image display method. Switch 1
The respective signals output from 9,20,21 are returned to analog signals by D / A converters 23,24,25 and G signals, B signals, R signals are output to terminals 26,27,28. In the above, the case of handling with frame signals was explained, but in the case of field signals, the capacity of all memories is
You can set it to 1/2.

〔The invention's effect〕

According to the present invention, it is possible to greatly reduce the no-signal time required for displaying a still image as compared with the conventional method by devising the control of the memory without providing a plurality of digital signal recording media. Therefore, a still image recording / reproducing device with good operation efficiency can be realized.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, second is a timing diagram showing a memory control method of the present invention, third and fourth.
The figure shows a pixel structure on a scanning line in the present invention. 10 to 12, 19 to 21: Switch, 13, 15, 17: First memory, 14, 16, 1
8: second memory, 22: control circuit, 29: optical disk.

Claims (4)

[Claims] 1. A still image signal composed of R (red), G (green) and B (blue) primary color signals is individually digitally encoded, temporarily stored in an image memory having a predetermined capacity, and read out. In this system in which the contents of the recording medium are transferred again to the image memory and the memory contents are repeatedly read out to reproduce the still image signal, n (n : An integer of 2 or more) image memory is provided, and digitally encoded R, G, and B signals are sequentially stored in the image memory of the n blocks so that each pixel is different, and the stored pixels are stored. Group signals are sequentially read in memory block units and transferred to the recording medium, and at the time of re-transferring the signals from the recording medium to the image memory, first, a signal of one pixel group of any one of the primary color signals Is the memory for each of the R, G, B signals. After the data is transferred to at least one memory block in the memory, the contents of these memory blocks are repeatedly read at the same time to display a monochrome image, and the signals of the remaining pixel groups are transferred from the recording medium to the predetermined memory blocks. A method for recording and reproducing still image signals, which is characterized in that 2. When one pixel group of one primary color signal is transferred from a recording medium to a memory block, the one pixel group is simultaneously transferred to one of the other memory blocks of the same primary color signal channel. A still image signal recording / reproducing system according to claim 1. 3. A pixel group corresponding to each primary color signal is transferred from the recording medium to a memory block of another primary color signal channel corresponding to the other memory block to which the pixel group of one primary color signal is transferred at the same time. The still image signal recording / reproducing system according to claim 2, wherein a read color image is displayed together with the one pixel group transferred at the same time. 4. The recording / reproducing system for a still image signal according to claim 1, wherein the one primary color signal is a G signal.