JPH02213278A - Facsimile decoding circuit - Google Patents

Abstract

PURPOSE:To eliminate necessity to read picture data for one line from a line memory when the picture data for one line are wholly blank and to execute two-dimensional decoding at high speed by setting the attribute information of the picture data for one line in the line memory. CONSTITUTION:A line memory circuit 2 is defined as the line memory, to which a referred line is stored, and a line memory circuit 3 is defined as the line memory, to which the picture data for one line after decoding are stored. When the data are decoded, a two dimensional decoding circuit 1 reads a flag F1 of the line memory circuit 2 and confirms the attribute of the picture information. When the attribute of the picture data is not wholly blank for one line, the picture data for the required number of words are read from the line memory circuit 2 as the referred line while decoded data 19 are inputted from a line. When the attribute of the picture data is wholly blank for one line, the picture data are not read from the line memory circuit but the two-dimensional decoding is executed only by inputting a code. Then, a decoded result is successively written to the line memory circuit 3 and when it is finished to write the picture data for one line, the attribute of the picture data is written to a flag F2.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a two-dimensional decoding circuit for a facsimile machine.

[Conventional technology]

A two-dimensional decoding circuit of a conventional facsimile machine outputs image data obtained by decoding received coded data by sequentially reading and referring to the coded data of the previous line stored in a reference line memory circuit.

[Problem to be solved by the invention]

The above-mentioned conventional two-dimensional decoding circuit performs two-dimensional decoding processing by decoding image data of the coded data to be decoded by referring to coded data sequentially read out from a reference line memory circuit that stores one line. Since it is output, there is a drawback that decoding time becomes long.

[Means to solve the problem]

The facsimile decoding circuit of the present invention includes a first line memory that stores one line of encoded data and attribute information of this encoded data, and a first line memory that stores one line of decoded image data and attribute information of this image data. image data that has been two-dimensionally decoded with reference to the second line memory that stores the image data, and the first memory that has written the encoded data that includes the attribute information received from the line and identified, and the image data of this image data. and a two-dimensional decoding circuit that writes attribute information into the second line memory.

〔Example〕

Next, the present invention will be explained with reference to the drawings. FIG. 1 is a block diagram of one embodiment of the present invention.

This embodiment includes a first line memory circuit 2 that stores code data for one line and attribute information (flag Fl) of this code data via a data line 11 in accordance with a write pulse 12 and an address signal 14, and a decoding circuit. A second line memory circuit 3 stores one line of image data and attribute information (flag F2) of this image data via a data line 15 in accordance with a write pulse 16 and an address signal 18; The image data decoded by referring to the data read out by the read pulse 13 and address signal 14 from the first line memory circuit 2 into which code data including the received and identified flag F1 was written and the flag F of this image data.
2 and a two-dimensional decoding circuit 1 for storing data in the second line memory circuit 2 via a data line 15 using a write pulse 16 and an address signal 18.

Next, the operation of this embodiment will be explained.

Flags Fl and F2 indicate the attributes of one line of image data stored in the line memory circuit 2.3, respectively. The line memory circuit 2 is a line memory in which a reference line is stored, and the line memory circuit 3 is a line memory in which one line of decoded image data is stored. When performing decoding, the two-dimensional decoding circuit 1 reads the flag F1 of the line memory circuit 2 and checks the attributes of the image data. If the attribute of the image data is not 1 line all white data (1 line all white), 0 image data is read out from the line memory circuit 2 as a reference line while inputting decoded data 19 from the line. When the attribute of 1 line is completely white, image data is not read from the line memory circuit, two-dimensional decoding is performed only by inputting the code, and the decoding results are sequentially written to the line memory circuit 3. When the image data writing is completed, the attributes of the image data are written to F2.

In this way, when the image data attribute indicates a completely white line, the image data is not read out and only the code is input, so that the decoding time can be speeded up.

〔Effect of the invention〕

As explained above, the present invention stores the attribute information of one line of image data in the line memory, so that when one line of image data is completely white, one line of image data is stored in the line memory. Since it is not necessary to read data from the data, there is an effect that two-dimensional decoding can be speeded up.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention. 1... Two-dimensional decoding circuit, 2.3... Line memory circuit.

Claims (1)

[Claims] a first line memory that stores one line of encoded data and attribute information of this encoded data; a second line memory that stores one line of decoded image data and attribute information of this image data; , the image data that has been two-dimensionally decoded by referring to the first memory in which coded data including the attribute information received and identified from the line is written and the attribute information of this image data are transferred to the second line. A facsimile decoding circuit comprising: a two-dimensional decoding circuit for writing into a memory.