JPH01195771A - Two-dimensional picture coding device - Google Patents

Abstract

PURPOSE:To attain high speed coding by storing a code subject to linear coding in place of recording a picture data itself to a reference line buffer and reducing the capacity of the reference line buffer. CONSTITUTION:A picture data A is stored in a large capacity picture buffer 10, a 2-dimension coding circuit 20 reads an existing line data A1 from the buffer, a linear coding circuit 1 applies the linear coding simultaneously to write a code data B0 to a reference line code buffer 2. The code data B0 is used as a data of the reference line in the processing of the next line. The 2-dimension coding circuit 20 reads the data of the reference line from the reference line code buffer 2 in a form of code data. Then 2-dimension coding circuit 20 writes the generated code data B into a code buffer 30 to complete the entire coding. Thus, the coding speed is quickened.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a two-dimensional image encoding device, and particularly to a two-dimensional image encoding device suitable for two-dimensional code compression of binary image data.

[Conventional technology]

A conventional example is shown in FIGS. 2 and 3. Among these, the conventional example shown in FIG. 2 is provided with a large-capacity image buffer IO in which each data of the current line and a reference line is stored in advance, and from this large-capacity image buffer IO, each line data Ao, At is read and encoded, and the resulting encoded data B is sent to the code buffer 30.
We have adopted the method of writing in .

Further, the conventional example shown in FIG. 3 has a reference line buffer 12 dedicated to storing the binary data of the previous line as is, and the one-dimensional encoding circuit 20 stores the reference line data A0 in the reference line data buffer 12. At the same time, current line data A is read from the large-capacity image buffer 10, encoded using this, and encoded data B is written to the code buffer 30.

[Problem to be solved by the invention]

However, in the conventional example shown in FIG. 2, image data at the same location in the large-capacity image buffer 10 needs to be accessed twice: once as a current line and once as a reference line. Furthermore, in the conventional example shown in FIG. 3, by providing the reference line data buffer 12, reading into the large-capacity image buffer 11 is only required once, but since reading is performed from the reference line data buffer 12, the number of accesses is limited to the second Same as in the figure. Furthermore, the conventional example shown in FIG. 3 has the disadvantage that the capacity of the reference line data buffer 12 is large, making it unsuitable for LSI (large scale integration).

Furthermore, each of these conventional examples has the disadvantage that the encoding speed is slow due to the large number of readings.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a two-dimensional image encoding device which improves the disadvantages of the conventional example and particularly improves the encoding speed.

[Failure to solve the problem]

Therefore, in the present invention, an image buffer that temporarily stores input image data, a two-dimensional encoding circuit that encodes current line data related to the image data stored in this image buffer based on previous line data, It is equipped with a code buffer that stores this encoded data and outputs it as necessary. Among these, the two-dimensional encoding circuit includes a one-dimensional encoding circuit that performs one-dimensional encoding of the previous line data, and stores the output of this one-dimensional encoding circuit and uses it as reference line code data as needed. A configuration is adopted in which a reference line code buffer is also provided for sending data to the dimensional coding circuit. This aims to achieve the above-mentioned purpose.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described based on FIG.

The embodiment shown in FIG. 1 includes an image buffer 10 that temporarily stores input image data A, and two systems that encode current line data related to image data A stored in this image buffer 10 based on previous line data. It includes a dimension encoding circuit 20 and a code buffer 30 that stores this encoded data and outputs it as necessary.

The two-dimensional encoding circuit 20 stores a one-dimensional encoding circuit 1 that performs one-dimensional encoding of previous line data, and stores the output of this one-dimensional encoding circuit 1, and uses this as reference line code data as necessary. A reference line code buffer 2 which is sent as B0 to the two-dimensional encoding circuit 20 is also provided.

Next, the operation of the above embodiment will be explained.

In FIG. 1, image data A is stored in a large-capacity image buffer 10.
The two-dimensional encoding circuit 20 reads the current line data A1 from there. At the same time, one-dimensional group coding circuit 1
Now, one-dimensional encoding is performed and code data B0 is written into the reference line code buffer 2. This code data B
0 is used as reference line data when processing the next line.

The two-dimensional code circuit 20 reads reference line data from the reference line code buffer 2 in the form of code data. The two-dimensional code circuit 20 writes the generated code data B into the code buffer 30, thereby completing the entire coding.

〔Effect of the invention〕

As described above, according to the present invention, a method is adopted in which the capacity of the reference line buffer is reduced by storing one-dimensional group encoded codes instead of recording the image data itself in the reference line buffer. It is possible to provide an unprecedented two-dimensional image encoding device that can reduce the number of accesses to the reference line buffer and increase the encoding speed.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing one embodiment of the present invention, and FIGS. 2 and 3 are block diagrams showing conventional examples, respectively. DESCRIPTION OF SYMBOLS 1... One-dimensional encoding circuit, 2... Reference line code buffer, 10... Large-capacity image buffer as an image buffer, 20... Two-dimensional encoding circuit, 30... Code buffer. Patent Applicant NEC Corporation Representative Patent Attorney Yuku Ami Takahashi

Claims (1)

[Claims] (1) An image buffer that temporarily stores input image data; a two-dimensional encoding circuit that encodes current line data related to the image data stored in this image buffer based on previous line data; In the two-dimensional image encoding device, the two-dimensional encoding circuit includes a one-dimensional encoding circuit that performs one-dimensional encoding of previous line data; A two-dimensional image encoding device comprising a reference line code buffer that stores the output of the one-dimensional code circuit and sends the output as reference line code data to the two-dimensional encoder circuit as needed.