JPS6242687A - Picture transmission method - Google Patents

Abstract

PURPOSE:To allow a receiving station to obtain necessary information as quickly as possible by transmitting picture data from blocks high in priority order. CONSTITUTION:When the top priority part lines near a scan line number 110, blocks 100, 101, 99, 102, 98, 103 and 97 are arranged in this order and are transmitted. In these blocks arranged in such a way, information (scan line number) blk# showing a position on a picture and data having column numbers 0, 1, 2,...254 and 255 in this order are arranged. Thus the receiving station can obtain necessary information as speedily as possible.

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention (Field of Industrial Application) The present invention relates to a digital image transmission method without feedback error control.

(Prior Art) Conventionally, the method of transmitting digital images using a television, facsimile, computer, etc. is as shown in FIGS. 4(a) and (b).
As shown in the figure, transmission was performed in a fixed order. That is, the digital image signal has scanning line numbers O11, 2, 210, 2 from the upper left of the image in 1 frame.
The data is arranged in the order of 11, and each block (scanning line) data includes column numbers 0, 1, . . . from the left side of the image.
The data is arranged in the order of 2, ---254.255. 5YNI is a frame synchronization character, and 5YN2 is a block synchronization character.

(Problems to be Solved by the Invention) In the above transmission method, since it is necessary to transmit one frame even when the necessary information does not cover the entire area of the image, there is a time problem when the transmission speed is slow. occurred.

In addition, in the conventional transmission method, in a receiving device of the type that improves the S/N by receiving image transmission N times, as shown in FIG.
As shown in C), it requires a reception time of NXT time, and S
There was a large amount of waste when receiving parts that did not require improvement in /N.

The present invention eliminates the drawbacks of the conventional method and transmits image data in order of importance (scanning lines), thereby enabling a receiving station to obtain necessary information as quickly as possible. The object of the present invention is to obtain an image transmission method that allows a receiving station to obtain an S/N ratio according to the importance of each part on an image.

"Structure of the Invention" (Means for Solving the Problems) In a data communication device that transmits digital image signals,
Information indicating the position on the image is added to each block (scanning!), allowing the transmitting station to arbitrarily transmit the blocks.

In addition, in the above transmission method, when blocks indicating the same pixel are repeatedly transmitted, the receiving station has a means for improving the S/N using the plurality of blocks, and the importance of each part on the image is The number of repetitions is set by giving weight to

(Operation) At the transmitting station (station A), the digital image signal is transmitted according to the scanning line transmission type and the number of repetitions listed in the table in the ROM in the microcomputer.

The receiving station (B station) transfers the received digital image data to the position corresponding to the scanning line specified by the information blk# indicating the position on the image added to each block (scanning line) at the time of transmission. Write.

Further, when it is necessary to improve the S/N, S/N improvement processing is performed. A specific method for the S/N improvement process may be a general method such as an error correction method.

FIGS. 2(a) and (b) show, for example, a case where the highly important part is around the scanning line number lOO, and each block (scanning line) is 100, ioi, 99.102.98.103.
．． 97.104.96,...1.210.01211
They are arranged and transmitted in this order.

Each block (scanning line) arranged in the above order has data indicating the position on one image (scanning line number) blk# and column number 0.1.2, φ, 254.255. are arranged.

SYN is a block synchronization character, and EOT is a transmission end code.

By transmitting in this way, if a highly important part is near scanning line number 100, it will be transmitted alternately above and below scanning line number 100, so that important parts can be quickly and easily compared to the conventional method shown in Figure 4. A partial image can be obtained. This is particularly useful in medium and low speed communication systems.

In addition, in FIG. 2(C), the image data block at scanning line number 1'00 is repeatedly transmitted eight times, and the image data block at scanning line number 1'00 is transmitted repeatedly.
If the number of repetitions in the ROM in the microcomputer is set so that the image data blocks at scanning line numbers O and 99 are transmitted repeatedly seven times, and the image data blocks at scanning line numbers O and 211 are transmitted only once thereafter. shows.

In this way, the S/N around scanning line number 100, which is highly important, will be improved. This is useful in systems that use radio and have a high error rate.

(Example) An example of an apparatus for specifically implementing the method of the present invention will be described below with reference to the drawings.

In FIG. 1, the transmitting station (station A) has video input terminal 1.
．． A/D converter 2, microcomputer MC (including video input/output controller 3, video RAM 4, CPU 5, buffer RAM 6, ROM 7, serial board 8, level converter 9), D/A converter 1 upper monitor output terminal The receiving station (B station) also has the same configuration.

In the above configuration, video (image) from a video camera, television receiver, video tape recorder, etc. (not shown)
When a signal is applied to the video input terminal l, it is digitized by the A/D converter 2 as a 256×212 pixel, 256 color signal, and written to the video RAM 4 by the video input/output controller 3. The CPU 5 adds data added to each block and sends it from the serial port 8 at a constant transmission rate (for example, 1200 bps), and sends the image data modulated by the modem 13 connected to the interface 12 to the receiving station via wireless @ 14. (B station).

At the receiving station (B station), the image data received by the radio 14 is demodulated by the modem 13 connected to the interface 12, and is written into the video RAM 4 according to the information added to each block.
The image data of
(not shown).

The modem 13 used here is an MSK modem used for simple data transmission and line connection in wireless communication.

The flowchart for performing the above-mentioned functions and operations is shown in Fig. 3(a).
, shown in (b). (a) is a flowchart of the transmitting side, and (b) is a flowchart of the receiving side.

(Modification/Application Example) As a modification example of $1, as additional information to image data,
In addition to the scanning line number in the above embodiment, by adding second information indicating the block pattern of the image data, this second information can be detected even when the screen resolution changes, that is, when the number of pixels changes. appropriate transmission.

As a second modification, as additional information to image data,
By adding third information indicating the scanning direction of image data in addition to the scanning line number of the above embodiment, appropriate transmission can be performed based on this third information.

As a third modification, when wireless is used to transmit digital image signals, fourth information representing the address of the transmitting station is added in addition to the scanning line number in the above embodiment as additional information to the image data. As a result, when data transmission is time-division multiplexed, a receiving station can simultaneously receive images from a plurality of transmitting stations on the same frequency.

"Effects of the Invention" According to the present invention, when using a medium or low speed data communication system, by transmitting the part of the screen containing important information first, the necessary information can be transmitted without waiting for the reception of the screen to be completed. This can greatly improve time-related problems.

In addition, by image processing at the receiving station, it is possible to greatly improve the S/N of image transmission from small-scale systems that cannot perform feedback error control, unidirectional communication systems, and interplanetary satellites.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an example of an apparatus that specifically implements the method of the present invention, and FIG. 2 is for explaining the present invention, in which (a) is a data configuration diagram and (b) is a data configuration diagram. FIG. 1 is a diagram showing scanning of the video RAM 4, FIG. 3 is a diagram showing repeated transmission, and FIG.
(a) is a flowchart on the sending side, (b) is a flowchart on the receiving side, and FIG. 4 is for explaining the conventional method. (a) is a data configuration diagram, and (b) is a diagram showing scanning of image data. , (c) are diagrams showing repeated transmission. 1. φ video input terminal, 2. A/D conversion i, MC
---Q microcomputer, 3 --- video input/output controller, 4 * eΦ video RAM, 5 --- CP
U, 6-11-buffer RAM, 7...-ROM, 8φ
・・Serial port, 9 meetings @ φ level conversion, lO・・
・D/A converter, 11ee conflict monitor output terminal, 12@
-・Interface, 13・Saiken modem, 14--1
%&im patent applicant Trio Co., Ltd. 8 offices 21 (αn certain 4 +v] p) (αn certain

Claims (1)

[Claims] 1. In a data communication device that transmits digital image signals, information indicating the position on the image is added to each block (scanning line), and the transmitting station arbitrarily sets the transmission order of the blocks. An image transmission method characterized by making it possible to transmit images. 2. In a data communication device that transmits digital image signals, information indicating the position on the image is added to each block (scanning line), allowing the transmitting station to arbitrarily set the transmission order of the blocks, and further transmitting When blocks indicating the same pixel are repeatedly transmitted from the station, the receiving station has a means for improving the S/N using the plurality of blocks, and weights the importance of each part on the image. An image transmission method characterized by setting the number of times of repetition.