System for producing pixel image data from CCITT encoded pixel data
US4968135A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 10, 1989 |
| Grant date | Nov 6, 1990 |
| Priority date | — |
| Expiry date | Oct 10, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T9/005
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An image decoding apparatus including a Huffman decoder for decoding CCITT-encoded image information encoded in both one-dimensional and two-dimensional encoding to sequentially generate individual symbols each associated with a pixel run. A relative address decoder receives each symbol from the Huffman decoder and generates, in response thereto, an item of run length information and a color value representing the color of the pixel run. Finally, a run length decoder sequentially receives the successive items of run length information and uses them in generating sequential words for transmission to, for example, a display device. The run-length decoder iteratively receives run-length information comprising a length value and a data value and generates in response thereto a series of fixed-length data words of predetermined length. The run-length decoding apparatus includes a run pointer control circuit and a data word creator circuit. The pointer control circuit generates, in response to each item of run-length information, a pointer identifying the end, within the data word, of a run. In response to each pointer, the data word creator circuit inserts into the word data bits repres…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.