JPH0253388A - Still picture transmitting device - Google Patents

Abstract

PURPOSE:To eliminate the color dislocation or synchronization dislocation of a picture by writing decoding data, excepting for a lost line, from the receiving scanning line address of each scanning line to a receiving buffer memory and eliminating the dislocation for the phase of a horizontal synchronizing signal and the phase of a sub carrier in receiving PCM data when the data are read from the receiving side buffer memory. CONSTITUTION:One part data of decoding data Vx, 1-Vx and 910 of an X-th line are lost by the interruption of a transmitting path, decoding data (i), excepting for the X-th line, are written from a receiving scanning line address (h) of each scanning line to a receiving buffer memory 9. Accordingly, the dislocation for the phase of the horizontal synchronizing signal or the phase of the sub carrier in the receiving PCM data can be eliminated when the data are read from the receiving side buffer memory 9. Thus, the color dislocation or synchronization dislocation of the picture is eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a still image transmission device that transmits still images.

[Conventional technology]

Conventionally, one video frame of a television signal is differentially encoded within each scanning line, and the transmission transmission data is sent out.The reception section receives the transmission reception data and writes the decoded data in order from the first address of the reception side buffer memory. It was.

[Problem to be solved by the invention]

In the conventional method described above, when part of the received transmission data is lost due to a transmission line disconnection, all the decoded data received after the transmission line disconnection is written to the receive panzer memory and then read from the receive buffer memory. Because the phase of the horizontal synchronization signal or the phase of the subcarrier of the received PCM signal is shifted, when decoding it to a TV signal, the color becomes strange or synchronization is lost, resulting in the still image not being perfectly reproduced on the monitor. It had

[Means to solve the problem]

The present invention has been made to solve these problems, and the transmitter includes a transmitter buffer memory that temporarily stores the PCM signal and outputs the still image data read from the beginning of the video frame, as well as outputs the scanning line address. , an encoding circuit that inputs still image data, differentially encodes it within a scanning line, and outputs encoded transmission data; The receiver includes a separation circuit that separates and outputs a reception scanning line address and encoded reception data from the transmitted reception data, and a separation circuit that decodes the encoded reception data and outputs decoded data. Equipped with a decoding circuit and a reception buffer memory that performs control to write the data of each scanning line of decoded data in order from the address specified by the reception scanning line address and repeatedly read the data from the first address of the written data. It is.

[For production]

One video frame of a television signal is temporarily stored in a transmission buffer memory, and the still image data read from the beginning of the video frame is differentially encoded within each scanning line. The transmission transmission data is output by multiplexing the scanning line address, which is the address where the first data of each scanning line of the still image data was written, and the reception section outputs the reception scanning line address and encoded reception data from the received transmission reception data. , decode the encoded received data, output the decoded data, write the decoded data in order from the address indicated by the receive scan line address of the receive panzer memory, and write one video from the first address of the written data. Repeatedly read data for a frame.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram showing one embodiment of the present invention.
(a) shows the configuration of the transmitter, and (b) shows the configuration of the receiver. 2 is a block diagram showing details of the reception buffer memory 9 in FIG. 1, FIG. 3 is a timing diagram of signals in each part of FIGS. 1 and 2, and FIG. Transmission data e, transmission reception data f, (b) reception scanning line address h, (c) encoded reception data g, decoded data j,
(d) is the reset signal i, and (e) is the write pe! Represents address l.

As an example of the present invention, the number of scanning lines in one video frame is 525, and each scanning line is called the 1st line, the 2nd line, . . . 525th line from the beginning of one video frame, and -scanning line The following explanation will be given assuming that the number of data is 910 data.

In the transmitting section shown in FIG. 1(a), an input PCM signal a obtained by PCM encoding a television signal is input to an input terminal 1. The data of one video frame of the input PCM signal a is once written into the transmission buffer memory 2, and still image data b, which is data read from the beginning of the video frame of the written input PCM signal a, is sent to the encoding circuit. 3, and the scanning line address c (ADl
-AD525). The encoding circuit 3 manually inputs still image data b, performs differential encoding within each scanning line, and outputs encoded data d to the multiplexing circuit 4.

The multiplexing circuit 4 multiplexes the scanning line address C at the beginning of each scanning line of the input encoded data d, and outputs the transmission data e to the transmission line output terminal 5.

In the receiving section shown in FIG. 1(b), the transmission line input terminal 6
Transmission reception data r is input to the input transmission reception data f, and input transmission reception data f is input to the separation circuit 7.

The separation circuit 7 separates the received scanning line address h and encoded received data g from the transmitted received data f, and outputs a reset signal i to the receiving buffer memory 9 upon detection of the received scanning line address h. The decoding circuit 8 starts decoding from the first data in each scanning line of the encoded reception data g, and outputs the decoded data j to the reception buffer memory 9.

As shown in FIG. 2, the reception buffer memory 9 is reset by the buffer memory 9-1 and the reset signal i.
The write pel counter 9-2 is a 910-decimal counter that outputs the counted value from 0 to 909 to the buffer memory 9-1 as the write pel address l, which is the address for one frame from the start address of the data written to the buffer memory. 9 to output read address n
It is composed of a read video frame counter 9-3 of 10x525 decimal count. Data Vx, l to V of the Xth line of decoded data j input to the buffer memory 91
x, 910 is written from ADx, which is the address of the receiving scanning line address h of the
), data of each scanning line from the 1st line to the 525th line of the decoded data j is sequentially written from the received scanning line address h (ADI to AD525) of each line. The data written in the buffer memory 9-1 is repeatedly read out from the first address of the written data in accordance with the read address n.

The read received PCM signal is output to the output terminal 10.

Here, the decoded data Vx, l~■x, 91 of the Xth line
Even if some data of 0 is lost due to transmission line disconnection,
The decoded data i other than the X-th line is written to the reception buffer memory 9 from the reception scanning line address h of each scanning line,
This has the effect of eliminating the shift in the phase of the horizontal synchronization signal and the phase of the subcarrier of the received PCM data when reading from the receiving side buffer memory, thereby eliminating color shift and synchronization of the image.

〔Effect of the invention〕

As explained above, in the present invention, the transmitting section includes a transmitting buffer memory that temporarily stores a PCM signal and outputs still image data read from the beginning of a video frame, and also outputs a scanning line address, and a transmitting section that inputs the still image data. An encoding circuit that differentially encodes within a scanning line and outputs encoded transmission data, and a multiplexing circuit that outputs transmission transmission data with a scanning line address multiplexed at the beginning of each scanning line of the encoded transmission data to a transmission path. The reception unit includes a separation circuit that separates and outputs a reception scanning line address and encoded reception data from transmission reception data, a decoding circuit that decodes the encoded reception data and outputs decoded data, and a decoding circuit that separates and outputs the reception scanning line address and encoded reception data from the transmission reception data. A part of the decoded data is data is lost due to a transmission line disconnection, the decoded data other than the lost line is written to the reception buffer memory from the reception scan line address of each scan line, and the received PCM data is read from the reception side buffer memory. This has the effect of eliminating the phase shift of the horizontal synchronization signal and the phase of the subcarrier, thereby eliminating image color shift and synchronization loss.

[Brief explanation of the drawing]

1(a) is a block diagram of the transmitter, (b) is a block diagram of the receiver, FIG. 2 is a block diagram showing details of the reception buffer memory 9 of FIG. 1, FIG. 3 is the block diagram of the receiver, FIG. 3 is a timing chart of signals at various parts of the pro-tuta diagram shown in FIG. 2; 2... Transmission buffer memory, 3... Encoding circuit, 4
. . . multiplexing circuit, 7 . . . separating circuit, 8 . . . decoding circuit, 9 . . . receiving buffer memory.

Claims (1)

[Scope of Claims] The transmitter temporarily stores the PCM signal for one video frame of the television signal, outputs still image data read from the beginning of the video frame, and reads the beginning data of each scanning line of the still image data. a transmission buffer memory that outputs the scanning line address that is the written address; an encoding circuit that inputs the still image data and differentially encodes it within the scanning line and outputs encoded transmission data; The receiver includes a multiplexing circuit that outputs transmission data in which the scanning line address is multiplexed to the transmission line at the beginning of each scanning line, and the receiving unit converts the transmission reception data input from the transmission line into a reception scanning line address and encoded reception. a separation circuit that separates and outputs the data; a decoding circuit that decodes the encoded received data and outputs the decoded data; and a decoding circuit that decodes the encoded received data and outputs the decoded data; 1. A still image transmission device comprising: a reception buffer memory that performs control to repeatedly read out one video frame worth of data from the first address of the written data by sequentially writing the data.