JPS6064578A - Picture output device - Google Patents

Abstract

PURPOSE:To improve the processing speed by storing a quantized data to a bit map memory without storing it temporarily to a buffer memory when all the quantized value at each picture element of the quantized data for one scanning line's share obtained through decoding are identical. CONSTITUTION:A data transmitted while being compressed by a linear run length coding system is decoded at a decoding circuit 4. A detection circuit 6 detects the coincidence between consecutive number of a black picture element or white picture element obtained by the decoding circuit 4 and a picture element number corresponding to the lateral length stored in a register 5 and transmits a coincidence signal C to a flip-flop 11 and a write control circuit 7. When no coincidence signal C is obtained, the content of a buffer 8 is written in the bit map memory 10. When the coincidence signal C is obtained, a selection circuit 9 is controlled to write ''1'' or ''0'' to all of one scanning line's share depending on the content of a flip-flop 12 and the signal is written directly to the bit map memory 10.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field of the Invention The present invention relates to an image output device for displaying or recording an image provided as encoded data observed by rask scanning and compressed by a one-dimensional run-length code. .

(b) Background of the technology In recent years, telephone lines have been used to transmit still images such as facsimiles, and video conference systems and video telephones to transmit moving images.
In order to improve transmission efficiency and transmission speed, the transmitting side generally subdivides the image to be transmitted into pixels arranged in a matrix (square shape), and divides the pixels in the row and column directions of the matrix into the main scanning direction and the column direction, respectively. It is observed by rask scanning in the sub-scanning direction and quantized pixel by pixel (for example, black pixels and white pixels are binarized as binary data "1" and '0', respectively).

Further, this is compressed using a one-dimensional run-length code (for example, replaced by the number of consecutive black pixels or white pixels in the scanning line direction).

On the other hand, on the receiving side, this is displayed on an image display device or, in some cases, recorded using an image recording device such as a laser printer. ,−
In addition to the decoding circuit that decodes encoded data compressed by the dimensional run-length code, it divides nine display or recording surfaces into pixels arranged in a matrix, and divides the image to be output to the display or recording surface for each pixel. A bitmap memory for storing quantized data (for example, binary data) and a buffer for temporarily storing quantized data corresponding to one row of the matrix are provided, and the received encoded data is decoded one scanning line at a time. However, the image data is temporarily stored in a buffer as quantized data and then stored in a bitmap memory, and the image stored in the bitmap memory is output as it is to a display surface or a recording surface.

Note that the encoded data transmitted from the transmitting side is
As shown in the figure, data 1 representing the horizontal (X) dimension of the entire image and data 2 representing the vertical (Y) dimension of the entire image are attached to the beginning, and EOL (End
Of Line) 3.

(c) Prior art and problems In an image output device equipped with a bitmap memory and a buffer as described above, conventionally, quantized data obtained by decoding received encoded data one scanning line at a time is
After temporarily storing the data in the buffer, the writing speed is increased by writing, for example, 32 pixels at a time to the bitmap memory.

In addition, after decoding one scanning line separated by the EOL, the number of pixels for one scanning line is counted and compared with the data 1 representing the horizontal dimension, thereby eliminating errors that occurred during transmission. The presence or absence of the data is checked, and if an error is found, predetermined error processing is performed before writing to the bitmap memory.

In this way, the quantized data for one scanning line is temporarily stored in the buffer each time and then written to the bi-notoma knob memory, resulting in a drawback that it takes a long time to output two images.

(d) Object of the Invention An object of the present invention is to provide an image output device 1 for outputting an image given by a run-length code.

The purpose is to improve its output speed.

(e) Structure of the Invention In order to achieve the above object, the image output device according to the present invention should divide two display surfaces or recording surfaces into pixels arranged in a matrix pattern and output the divided pixels to the display surface or recording surface. A bitmap memory for storing an image as quantized data for each pixel, and a buffer for temporarily storing a predetermined length of quantized data to be written in the bitmap memory.
The image is observed by rask scanning for each pixel arranged in a matrix, quantized for each pixel, and then compressed by a one-dimensional run-length code.The image data provided as encoded data is decoded one scanning line at a time and In an image output device that temporarily stores it in a buffer, then stores it in the bi-notomasop memory and outputs it to a display surface or a recording surface, all the quantized values for each pixel of the quantized data for one scanning line obtained by the decoding are If the values are the same,
The information is stored in the bisotoma knob memory without being temporarily stored in the knob.

(f) Examples of the Invention The gist of the present invention will be specifically explained below using two examples.

FIG. 2 is a block diagram of one embodiment of the present invention.

4, the image is observed by rask scanning for each pixel arranged in a matrix, and each pixel is binarized with black pixels as "l" and white pixels as "0", and then compressed using a one-dimensional run-length code. receive the encoded data transmitted by
A decoding circuit decodes each scanning line and outputs a signal a representing the type of binary data (black pixel or white pixel) and a signal a representing the number of consecutive black pixels or white pixels; 5 is the transmitted code; A register 6 stores the length of the entire image in the horizontal direction, that is, the main scanning direction, in terms of the number of pixels, which is attached to the beginning of the encoded data. It detects a match with the number of pixels to be stored and outputs a match signal C.
7 is a detection circuit that sets the type of binary data represented by the signal C in the flip-flop 11 and the type of binary data represented by the signal C in the flip-flop 12. A write control circuit controls to prevent writing; 8 is a buffer for temporarily storing one line of binary image data to be written to the bitmap memory 10, which will be described later; 9 is a flip-flop 11 in which the coincidence signal C is not set; At times, the contents of the buffer 8 are written to the bitmap memory 10, and when the match signal C is sent to the flip-flop 11, "1" is written to all of one scanning line according to the contents of the flip-flop 12.
This is a selection circuit that selects whether to write "" or "0".

With the above configuration, when all the pixels of one scanning line are black or white, after being decoded by the fjj circuit 4, they can be directly stored in the bitmap memo 1/0 without temporarily storing them in the buffer 8. I can do it.

Writing data to the buffer 8 is generally done for 8 pixels at a time, so it takes several times as much time as writing to the bi-notemanpmemo i month 0, but according to the above embodiment, the output time for 9 images is significantly reduced. can be shortened to

(g) Detailed Description of the Invention According to the present invention, in an image output device that decodes and outputs an image given as encoded data compressed by a one-dimensional run-length code one scanning line at a time. , its output speed can be improved.

[Brief explanation of the drawing]

FIG. 1 is a data format of image data received by an image output device, and FIG. 2 is a process diagram of an embodiment of the present invention. In the figure, 4 is a decoding circuit, 6 is a detection circuit, 8 is a buffer, and 9
1 is a selection circuit, and 10 is a bitmap memory.

Claims (1)

[Claims] A display surface or recording surface is divided into pixels arranged in a matrix, and an image to be outputted to the display surface or recording surface is written to a bitmap memory for storing quantized data for each pixel, and to the bitmap memory. A buffer for temporarily storing quantized data of a predetermined length is provided, and one image is observed by rask scanning for each pixel arranged in a matrix, quantized for each pixel, and then compressed by a one-dimensional run-length code. In an image output device that decodes image data given as data one scanning line at a time, temporarily stores it in the buffer, stores it in the bitmap memory, and outputs it to a display surface or a recording surface. An image output device characterized in that when all the quantized values for each pixel of the quantized data of a line segment are the same value, the quantized values are stored in the bitmap memory without being temporarily stored in the buffer.