Image data compression apparatus for compressing both binary image data and multiple value image data

• US 6,941,023 B2
• Filed: 03/19/2002
• Issued: 09/06/2005
• Est. Priority Date: 03/21/2001
• Status: Active Grant

• Current Assignee: Ricoh Company Limited
• Original Assignee: Ricoh Company Limited
• Inventors: Shiraishi, Naoto
• Primary Examiner(s): Johns, Andrew W.
• Assistant Examiner(s): Alavi, Amir
• Application Number:
  US10/100,776
• Publication Number:
  US 20030053701A1
• Time in Patent Office: 1,267 Days
• Field of Search: 382/232, 382/238, 382/239, 382/244, 382/245, 382/251, 375/240.02, 375/240.03, 375/240.12, 341/59
• US Class Current: 382/245
• CPC Class Codes: G06T 9/004 Predictors, e.g. intraframe, interframe coding
• CPC Class Codes: G06T 9/005 Statistical coding, e.g. Huffman, run length coding
• CPC Class Codes: H03M 7/46 Conversion to or from run-length codes, i.e. by representing the number of consecutive digits, or groups of digits, of the same kind by a code word and a digit indicative of that kind
• CPC Class Codes: H04N 1/41 Bandwidth or redundancy reduction by scanning H04N1/17 ; methods or arrangements for coding, decoding, compressing or decompressing digital video signals H04N19/00
• CPC Class Codes: H04N 1/419 in which encoding of the length of a succession of picture-elements of the same value along a scanning line is the only encoding step H04N1/4135 - H04N1/417 take precedence
• CPC Class Codes: H04N 19/93 Run-length coding

Abstract

An image data compression apparatus which compresses code data obtained by compressing image data by a fixed length encoding method so as to reduce a scale of hardware and reduce a development cost of software for an image data compression a binary image data processing part processes binary image data in accordance with a run length encoding method, the binary image data processing part including an encoding part which encodes run lengths of the binary image data by an encoding part. A multiple value image data processing part processes multiple value image data in accordance with a prediction encoding method. The encoding part of the binary image data processing part is commonly used by the multiple image data processing part so that the encoding part compresses both the binary image data and the multiple value image data.

Claims

1. An image data compression apparatus, comprising:

a binary image data processing part which processes binary image data in accordance with a run length encoding method, said binary image data processing part including an encoding part which encodes run lengths of the binary image data by an encoding part; and

a multiple value image data processing part which processes multiple value image data in accordance with a prediction encoding method,

wherein said encoding part of said binary image data processing part is commonly used by said multiple image data processing part so that said encoding part compresses both the binary image data and the multiple value image data.

2. An image data compression apparatus as claimed in claim 1, wherein:

said binary image data processing part comprises a run length processing part including;

means for preparing a predetermined number of run lengths corresponding to a number of bits included in a plurality of bit patterns processed in parallel, and obtains a run length to be carried over to a subsequent pattern; and

means for summing the run length to be carried over and the run lengths of the subsequent bit pattern, and

said multiple image data processing part comprising a prediction encode processing part which receives a fixed length code of the multiple image data, and separates parameters having a high consecution correlation from a quantized code part of the fixed length code so as to apply prediction encoding only to the separated parameters to generate a plurality of prediction codes.

3. The image data compression apparatus as claimed in claim 2, wherein said encoding part comprises:

a repeat processing part which detects a number of repeats in a plurality of runs or the prediction codes so as to generate a repeat number; and

an encode processing part which encodes the plurality of runs or the prediction codes, the quantized code part of the fixed length code and the repeat number.

4. An image data compression apparatus for compressing multiple value image data, comprising:

a prediction encode processing part which receives a fixed length code of the multiple image data, and separates parameters having a high consecution correlation from a quantized code part of the fixed length code so as to apply prediction encoding only to the separated parameters to generate a plurality of prediction codes;

a repeat processing part which detects a number of repeats in the plurality of prediction codes so as to generate a repeat number; and

an encode processing part which encodes the plurality prediction codes, the quantized code part of the fixed length code and the repeat number.

5. An image data compression method for compressing multiple value image data, the method comprising the steps of:

receiving a fixed length code of the multiple image data;

separating parameters having a high consecution correlation from a quantized code part of the fixed length code;

applying prediction encoding only to the separated parameters so as to generate a plurality of prediction codes;

detecting a number of repeats in a plurality of prediction codes so as to generate a repeat number; and

encoding the prediction code, the quantized code part of the fixed length code and the repeat number.