JPS6242686A - Picture transmission method - Google Patents

Abstract

PURPOSE:To eliminate continuous generation of errors and to speedily obtain minimum information required by digitizing a picture signal, executing the jumping transmission of scan lines in the horizontal or vertical direction in picture scanning and forming one picture with plural fields. CONSTITUTION:In digitized picture signals, even-numbered scan line numbers 0, 2,...208 and 210 are made into the 1st field, while the odd-numbered scan line numbers 1, 3,...209 and 211 are made into the 2nd field. Scan line numbers 1, 3,...209 and 211 are jumped and transmitted every two lines. Upon the completion of transmission of the 1st and 2nd fields, transmission of one picture is also terminated. Thus continuous errors are eliminated, and the minimum information required can be quickly obtained.

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, in the transmission of images using voice bands such as facsimiles and the transmission of digitized images using computers, the images are transmitted sequentially starting from the upper left, as shown in Figures 4(a) and (b). It was common to do so. That is,
The digital image signal has scanning line numbers O1l, 2, III, 209.210.21 from the upper left of the image in one frame.
The data is arranged in the order of 1, and each block (scanning line) data contains column numbers 0.1.2 from the left side of the image.
, ll11.254.255. SYN is a frame synchronization character.

(Problem to be solved by the invention) In this method of sequential transmission, the receiving station cannot obtain the necessary information unless it waits for the time T required to transmit one screen, and If the image is disturbed over several or more scanning lines, there is a drawback that the image in that area is largely missing, as shown in FIG. 4(C).

The present invention solves the above-mentioned drawbacks, obtains necessary information in a time of T/n, where T is the time for transmitting image data sequentially, and n is an skip interval, and the number of times during transmission is An object of the present invention is to obtain an image transmission method that allows a receiving station to recognize a portion of an image even when disturbances occur over more than one scanning line.

"Structure of the Invention" (Means for Solving the Problems) An image signal from a television camera, television receiver, video cheese recorder, etc. is digitized, and scanning line interlace transmission is performed in the horizontal or vertical direction of image scanning, A plurality of fields constitute one screen, and data is transmitted between the five transmitting stations and the receiving station using a medium/low speed data communication device.

(Function) When configuring one screen with two fields, as shown in Fig. 2 (a
), (b), the digitized image signals are divided into even-numbered scanning line numbers 0, 2, .
- The scanning line number 1.3 is set with the input 209.211 as the second field, and the red 209.211 is skipped and transmitted every other scanning line, and when the transmission of the first and second fields is completed, it is 1. Allow screen transmission to end.

If it is transmitted in this way, compared to the conventional method shown in Fig. 4, the result will be 】/2
You can see that you can get the information you need in just a few minutes.

Furthermore, as shown in FIG. 2(C), even if disturbances occur over multiple scanning lines during the image transmission of the first field, it is compensated for by the image transmission of the second field, so that the image can be recognized. is obtained.

(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 Figure 1, the transmitting station (station A) has a video input terminal "/
-1, A/D converter? , microcomputer MC (video input/output controller 3, video RAM 4, CPU 5
, buffer γRAM 6, ROM 7, serial port 8, level 11/converter 9), D/A converter 10, monitor output terminal 11, interface (R5-232C)
12. It consists of a modem 13 and a wireless* (FM communication device, etc.) 14, and the receiving station (B station) also has the same configuration.

- In the configuration described above, video (
When an image) signal is applied to video input terminal 1, the A/D
The converter 2 digitizes the signal as a 256×212 pixel, 256 color signal, and the video input/output controller 3 writes the signal into the video RAM 4. The CPU 5 sends the image data from the video RAM 4 through the serial port 8 at a constant transmission rate (for example, 1200 bps), and transmits the image data modulated by the modem 13 connected to the interface 12 to the receiving station (station B) via the radio 14. ).

At the receiving station (station B), the image data received by the radio 14 is demodulated by the modem 13 connected to the interface 12 and written into the video RAM 4. The image data from the video RAM 4 is converted into analog by the D/A converter 10 via the video input/output controller 3.
It is visualized by a monitor (not shown) such as a CRT display connected to the monitor output terminal 11.

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

The flowchart for carrying out the above-mentioned action is shown in Fig. 3(a).
, (b), in which (a) is a flowchart of the transmitting side and (b) is a flowchart of the receiving side.

Although FIG. 2 shows an example in which one screen is composed of two fields, transmission may be made such that one screen is composed of three or more fields as long as the image is recognizable.

"Effects of the Invention" According to the present invention, in the case of an image communication system having a CRT display controlled by a microcomputer, only slight changes are made to the software of the conventional method.
It is more resistant to continuous errors than before, and the minimum necessary information can be obtained quickly.

[Brief explanation of the drawing]

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 the scanning of the video RAM 4 in FIG. 1, FIG. 3 is a diagram showing image disturbance due to disturbance, FIG. (b) is a receiving side flowchart, FIG. 4 is for explaining the conventional method, (a) is a data configuration diagram, (b) is a diagram showing scanning of image data, and (C) is an image due to disturbance. FIG. 1. Video input terminal, 2. A/D converter, MC
...Microcomputer 3 *Contest*Video input/output controller, 4...Video RAM, 5Content - Contest CP
U, 6th race...bar 2hua RAM, 7th race Q・ROM, 81
1. Serial port, 9. e-level converter, 10. D/A converter, 11** and monitor output terminal, 12.
---Interface, 13---Modem, 14Φ-
-mmm Patent Applicant Trio Co., Ltd. 8-Ken Inkstone 2I Fu(aan(A)CC) 24 Figure (a)

Claims (1)

[Claims] When transmitting a digital image signal using a medium/low speed data communication device, image transmission is characterized by carrying out interlaced transmission of scanning lines in the horizontal or vertical direction of image scanning, and configuring one screen with a plurality of fields. Method.