Image processing apparatus
US6330076A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 31, 1997 |
| Grant date | Dec 11, 2001 |
| Priority date | — |
| Expiry date | Oct 31, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/646
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An image processing apparatus has a data conversion unit which converts RGB image data of a document to luminance component and chromaticity component, an optimization process unit which converts the distribution state of the luminance component data and chromaticity component data so as to achieve a distribution from a minimum value to a maximum value of the data within a color space, an encoding process unit which encodes data of each pixel as code data obtained by quantization at a gradient level less than the data within a range of gradient distribution based on mean value information, a memory which stores mean value information, gradient range exponent, and code data of each block obtained by the encoding process in the encoding unit, a decoding process unit which decodes code data in block units based on the mean value information and gradient range exponent stored in the memory, and reverse optimization process unit which returns the distribution state of data of the luminance component and chromaticty component decoded in the decoding process unit to a state prior to conversion in the optimization process unit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.