Coding apparatus, decoding apparatus, coding method, decoding method, amd computer-readable recording medium for executing the methods
US6788811B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | May 5, 2000 |
| Grant date | Sep 7, 2004 |
| Priority date | — |
| Expiry date | May 5, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N19/63
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A coding apparatus which can simplify a coding circuit and also simplify the processing of quantization. Image data that consists of R-, G-, and B-color components read from a scanner into buffers is subjected to transformation using a position correlation for each of RGB in position-correlation transformation sections. The DC component of each of the components is then color-converted in a color conversion section to be a DC lightness signal and DC color signals, and the signals are quantized in a quantization section and a coding section. Whereas, the AC components of each of the components are subjected to quantization in a first step in an AC component quantization section, and further to color conversion in a color conversion section to be an AC lightness signal and AC color signals. The signals are quantized in a second step in a quantization section and a coding section.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.