Data processor
US5875041A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 25, 1996 |
| Grant date | Feb 23, 1999 |
| Priority date | — |
| Expiry date | Jan 25, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N19/30
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
In a data processor, in order to perform coding efficiently, image data of a prescribed pixel matrix is subjected to orthogonal transformation to coefficient data. Obtained coefficient data is quantized with a first quantization table for character image, and they are also quantized with a second quantization table for half-tone image. Then, the image data is discriminated to be a character image data or a half-tone image data according to the two quantization data. Then, quantization data in correspondence to the discrimination is subjected to entropy coding. In a different data processor, in order to discriminate a kind of image in a processing block fast and correctly, image data are divided into first processing blocks of m*m pixel matrices and second processing blocks of M*M pixel matrices wherein M>m. For example, m=8 and M=16. A second processing block includes one of first processing blocks and adjacent pixels around it. Image data in a first processing block and image dat in a second processing block including the first processing block are subjected to orthogonal transform to send coefficient data, respectively. It is discriminated according to the coefficient data of the…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.