JPH04290380A - Picture information transfer system - Google Patents

Abstract

PURPOSE:To improve run-length encoding efficiency to keep multi-bit change due to the carry as in the binary expression by expressing binary code for each picture element information using a Gray code. CONSTITUTION:Picture element information digitized in an A/D converter 1 is converted into the Gray code by a binary/Gray(B/G) converter 8 on the transmission, then stored in a picture element memory 2 corresponding to each picture element. The information in the memory 2 is read out in the prescribed order, the run-length encoding is performed by a run-length encoder 3. Further, it is demodulated by a demodulator 4 and transmitted to a transmission path. On the other hand, the information on the memory 2 is read out when information for all picture element is stored in the memory 2 on the reception. After the information is converted into a binary code by a G/B converter 9, the digital transfer of picture element information is performed through reproduction by displaying or printing the information by an output device 7.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image information transmission system for digitally transmitting image information after band compression.

0002

2. Description of the Related Art FIG. 3 is a block diagram showing the configuration of a transmitter (a) and a receiver (b) of an image transmission apparatus that implements a conventional image information transmission system. , 1 is an A/D converter that digitizes information (luminance or color information) corresponding to each pixel forming an image, and 2 is an A/D converter that stores the output of the A/D converter 1 in units of pixels. a pixel memory; 3 a run-length encoder that reads data stored in the pixel memory 2 in a fixed order and performs run-length encoding; 4 encodes image information encoded by the run-length encoder 3; This is a modulator that sends out signals to a transmission line such as a telephone line.

On the other hand, 5 is a demodulator that demodulates the encoded signal received via the transmission path, and 6 is a run that decodes the encoded signal demodulated by the demodulator 5 into information corresponding to each original pixel. The length decoder 7 is an output device that reads out the output of the run length decoder 6 stored in the pixel memory 2 in a fixed order and displays or prints it out.

Next, the operation will be explained. First, on the transmitting side, the pixel information digitized by the A/D converter 1 is temporarily stored in the pixel memory 2, and the MSB (most significant bit) of the luminance information is read out in a predetermined order, for example, for all pixels in one row. , and then sequentially reads out the next bit for each row. This read information is run-length encoded by a run-length encoder 3, further modulated by a modulator 4, and sent to a transmission path.

On the receiving side, the coded signal demodulated by the demodulator 5 is decoded by the run-length decoder 6 into information corresponding to each original pixel and stored in the pixel memory 2. Then, when the information for all pixels is stored in the pixel memory 2 (at this point, the pixel memories 2 on the transmitting side and the receiving side have the same contents), the information stored in the pixel memory 2 is stored in the pixel memory 2. Digital transmission of the image information is performed by displaying or printing out the content using the output device 7 and reproducing the content.

[0006]

[Problem to be Solved by the Invention] Since the conventional image information transmission system is configured as described above, it is possible to encode the image information with a good compression rate when there is little change between each pixel of the image information to be transmitted. However, if there is a change between the pixels, there is a problem that the compression efficiency of encoding decreases. Note that similar prior art includes, for example, Japanese Patent Application Laid-open No. 60-2837.
There are publications such as Publication No. 4.

The present invention has been made to solve the above-mentioned problems, and aims to provide an image information transmission method that improves the encoding and compression efficiency of image information even when there is a change between adjacent pixels. The purpose is

[0008]

[Means for Solving the Problems] The image information transmission method according to the present invention converts the pixel information of each pixel constituting the image information into a Gray code to reduce bit changes in the pixel information, and then performs a run. Length encoding is performed, band compression is performed, and digital transmission is performed.

[0009]

[Operation] The image information transmission system of the present invention expresses the binary code of each pixel information using a Gray code, so that the LSB (least significant bit) of the pixel information
It also improves the efficiency of run-length encoding, since a 1-bit change results in only a 1-bit change per pixel, rather than a multi-bit change due to carry, as in the case of binary representation.

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of a transmitting section (FIG. 1(a)) and a receiving section (FIG. 1(b)) of an image transmission apparatus that realizes an image information transmission system according to an embodiment of the present invention.
The same or equivalent parts as in the conventional image transmission device (FIG. 3) are given the same reference numerals, and the description thereof will be omitted.

In the figure, reference numeral 8 denotes a binary/gray converter (hereinafter referred to as a B/G converter) for converting the binary code output from the A/D converter 1 into a gray code;
is a gray/binary converter (hereinafter referred to as a G/B converter) that converts the gray code read from the pixel memory 2 into a binary code on the receiving side.

Next, the operation will be explained. First, on the transmitting side, the pixel information digitized by the A/D converter 1 is converted into B
After the code is converted into a Gray code by the /G converter 8, it is temporarily stored in the pixel memory 2 in association with each pixel. Then, the information in the pixel memory 2 is read out in a predetermined order, run-length encoded by a run-length encoder 3, and further modulated by a modulator 4 and sent to a transmission path.

An example of conversion in the B/G converter 8 is shown in FIG. Note that in this example, the pixel information is 4 bits, and conversion from binary code to Gray code or from Gray code to binary code can be easily performed using cascade connection of EXCLUSIVE OR or ROM. .

On the receiving side, the encoded signal demodulated by the demodulator 5 is decoded by the run-length decoder 6 into information corresponding to each original pixel and stored in the pixel memory 2. When the information for all pixels is stored in the pixel memory 2, the information (gray code) in the pixel memory 2 is read out, converted into a binary code by the G/B converter 9, and then displayed or displayed by the output device 7. Digital transmission of image information is performed by printing out and reproducing the image information.

[0015]

As described above, according to the present invention, each pixel information constituting image information is converted into a Gray code to reduce bit changes in the pixel information, and then run-length encoding is performed. Since band compression is used for digital transmission, even when information on adjacent pixels changes, there is an effect of reducing a decrease in compression efficiency of run-length encoding.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of an image transmission device that implements an image information transmission method according to an embodiment of the present invention.

FIG. 2 is a diagram showing an example of conversion between a binary code and a Gray code.

FIG. 3 is a block diagram showing the configuration of an image transmission device that implements a conventional image information transmission method.

[Explanation of symbols]

1 A/D converter 2 Pixel memory 3 Run-length encoder 4 Modulator 5 Demodulator 6 Run length decoder 7 Output device 8 B/G converter 9 G/B converter

Claims (1)

[Claims] Claim 1: In an image information transmission method in which image information is band-compressed and digitally transmitted, the pixel information of each pixel constituting the image information is converted into a gray code to reduce bit changes in the pixel information. This image information transmission method is characterized in that after that, run-length encoding is performed, band compression is performed, and digital transmission is performed.