JPS62261295A - Image transmission converting device - Google Patents

Abstract

PURPOSE:To transmit and receive the picture of a color as a still picture with a general public line by A/D-converting the composite video signal of an image for one picture, executing the storing on a memory and executing successively the modulating processing of a sound band with a slow scanning. CONSTITUTION:The composite signal from a video camera is inputted to a video signal input terminal 10, divided into red, green and blue by a hue detecting device 11, an A/D converter 12 digitizes respective 320 dotsX200 dots and 4-bit gradation for red, green and blue and stores them once. The stored data read the data in the horizontal direction by the slow scanning of about 0.5 seconds for one line, a D/A converter 16 makes them into red, green and blue analog signals, an SCFM modulator 17 executes the FM modulating signal processing of a sound band, and the telephone set for a general public line transmits them as a sound signal with the speaker 19 of a sound coupler 18. Thus, the photographed image can be transferred as the still picture.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an image transmission/conversion device that transmits a video signal captured by a video camera to a remote location using a general telephone line.

"Prior Art" Conventionally, when transmitting and receiving image data, there are two methods: analog transmission and digital transmission.

``Problems to be solved by the invention'' Analog transmission requires a frequency band of 5 MH2 or more, which requires dedicated lines such as VHF or higher radio waves, coaxial cables, optical fiber cables, etc., and equipment costs are high. ,
Images could only be sent and received between arbitrary locations with equipment.

Furthermore, in the case of digital transmission, a modem is used to transmit and receive data as 1 and O signals, so it takes a very long time to transmit and receive one screen of image data. Also, the use of high-speed digital communication networks has the same problems as analog transmission.

Furthermore, when transmitting and receiving images at a remote location, dedicated equipment and dedicated transmission lines are required, which incurs equipment and operating costs, and the transfer locations are limited to locations with dedicated equipment. Furthermore, when using a general public line, images are sent and received as bit signals using a modem, so it takes a very long time to send and receive high-resolution images. For example, a 256 dot x 256 dot, 4-bit gradation color image has 1200 pixels.
If you send it without any procedure using a Bau modem, it will take about 655 seconds/1 screen.

"Means for Solving the Problems" The present invention provides a method for converting a composite video signal of an image into an A/D video signal for one screen.
The signal is converted into D, temporarily stored in memory, and modulated in the audio band by sequential slow scanning. Approximately 9 digits per screen are transmitted using an acoustic coupler and a general public line for voice band signals.
Transfer in 0 seconds. At the transfer destination, the audio band signal is demodulated and, after D/A conversion, is output as a composite video signal or a high frequency signal.

``Operation'' Image data is transmitted and received using audio band signals using an acoustic coupler, so a color screen can be transmitted and received as a still image over general public lines. Since input and output are composite video signals, commercially available video cameras and televisions can be used to imitate and output images.

"Example" Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is an example of a device configuration for transferring image data using an image transmission/conversion device. The image captured by the video camera 1 is output as a composite video signal and input to the image transmission converter 2a.

The image transmission converter 2a modulates the composite signal into an audio band image signal and transmits the signal to the acoustic coupler 3a and the receiver 5 of the telephone 4a.
The audio signal is input to the image transmission converter 2b via the public line 6 through the speaker and microphone of the telephone 4b and the microphone and speaker of the acoustic coupler 3b. The image converter 2b demodulates the audio signal and outputs it as a composite video signal to the television 7 and the video camera 1.
It is possible to display the imitated image as a still image.

Still images can also be printed on the video printer 8.

FIG. 2 is a block diagram of the image transmission/conversion device. A composite signal from the video camera shown in FIG. 1 is input to the video signal input terminal 10 shown in FIG. Each image is digitized with 320 dots x 200 dots and 4-bit gradation and temporarily stored in the video memory 13.

The stored data is read out in the horizontal direction of the image in a slow scan of about 0.5 seconds per line under the control of the memory control unit 15 when the transmission switch of the switch 14 is pressed, and the data is read out in red by the D/A converter 16. , green, and blue analog signals, and the SCFM modulator 17 converts them into audio band (350
~3.2 KHz> is subjected to FM modulation signal processing and transmitted as an audio signal through the speaker 19 of the audio coupler 18 through a telephone set for a general public line.

The transmission destination receives an audio signal from the telephone with the microphone 20 of the acoustic coupler 18, demodulates the FM modulated signal with the SCFM demodulator 21, digitizes it with the A/D converter 22, and sends it to the video memory 13. memorize it once. The stored data is converted into an analog signal by a D/A converter '23, and then outputted as a composite signal by a color encoder 24 to a video signal output terminal 26, and an image captured by a video camera is output to a TV having a video input terminal. can be displayed as a still image. For TVs that do not have a video input terminal, the composite video signal is
The modulator 25 can output the signal as a television channel signal.

Since this device can transmit and receive image data as analog signals in the audio band, it can also record image data on audio cassette tapes. TAP
E PLAY input 27, TAPE REC output 28
, RF output 29, RX input 30. for radio equipment. It is equipped with terminals such as a TX output 31.

"Effects of the Invention" Since the present invention sends image data using general public lines, there is no need for dedicated equipment or dedicated lines like in a video conference system, and as long as there is a telephone, it can be placed anywhere and is inexpensive. Color images can be sent and received.

Furthermore, when an image is converted into a digital signal and sent and received by a modem (1200 baud, color screen 256 dots x 256 dots, 655 seconds with 4-bit gradation), the image can be transmitted faster (96 seconds under the same conditions as above).

[Brief explanation of drawings]

FIG. 1 is a block diagram of a device for transmitting image data using an image transmission/conversion device. FIG. 2 is a block diagram of the image transmission/conversion device. The memory control unit 17.21 is an SCFM modulator 18, an acoustic coupler 23, and a D/A converter 24 is a color encoder.

Claims (1)

[Claims] An A/D modulator that converts a composite video signal, a video memory that temporarily stores its output as a color still image, a memory control unit that sequentially slow scans the stored data and performs audio band modulation processing, and an SCFM.
The transmitting side is equipped with a modulator and an acoustic coupler that transmits image data as an audio signal via a general telephone line, and the receiving side is equipped with an SCFM demodulator and D that demodulates the audio signal.
An image transmission/conversion device comprising a D/A converter and a color encoder for converting the A/A signal and outputting it as a hipposite video signal.