Title:
IMAGE CODING METHOD AND APPARATUS, IMAGE DECODING METHOD AND APPARATUS, IMAGE FORMING APPARATUS AND RECORDING MEDIUM
Document Type and Number:
Japanese Patent JP3867886
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To attain a highly efficient compression of dither image data whose dither threshold is unknown or varying and compression of error diffusion image data whose error diffusion coefficient is unknown or varying.
SOLUTION: In an image coding apparatus, image data are encoded by a processing unit of a block composed of a plurality of pixels. A statistical part 102 extracts statistical information of pixel values for every position in the block out of a plurality of encoded blocks in the vicinity of a coding target block. A coding processing part 103 performs coding processing of the target block by using the statistical information extracted at the statistical part 102. The processing part 103 is composed of, for example, a prediction part 113 to predict values of coding target pixels from reference pixels selected based on the statistical information, a comparison part 111 to detect an error between the predicted values and the values of coding target pixels and a coding part 112 to perform entropy coding of the predicted error.
Inventors:
Takahiro Yanagishita
Hiroshi Suzuki
Hiroshi Suzuki
Application Number:
JP2000268618A
Publication Date:
January 17, 2007
Filing Date:
September 05, 2000
Export Citation:
Assignee:
株式会社リコー
International Classes:
H04N1/41; H03M7/40; H04N19/103; H04N19/13; H04N19/137; H04N19/176; H04N19/194; H04N19/196; H04N19/50; H04N19/503; H04N19/91; (IPC1-7): H04N1/41; H03M7/40; H04N7/32
Domestic Patent References:
| JP6152978A | ||||
| JP8186717A | ||||
| JP7222162A | ||||
| JP57021168A | ||||
| JP60012865A | ||||
| JP2002077628A | ||||
| JP4019075U |
Attorney, Agent or Firm:
Makoto Suzuki
Kazuhito Oura
Kazuhito Oura