Method of encoding image pixel values for storage as compressed digital data and method of decoding the compressed digital data
US5270812A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 22, 1991 |
| Grant date | Dec 14, 1993 |
| Priority date | — |
| Expiry date | Jul 22, 2011 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N5/85
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method of encoding an image for CD-I players comprises obtaining the pixel information as a first matrix (M1) of 768.times.560 pixel component values, decimation filtering (1) the first matrix (M1) to produce a second matrix (M2) of 384.times.560 pixel component values, encoding (2) the second matrix (M2) to produce a first set of DYUV digital data (RDD1) for storage on a compact disc (SM), applying the digital data (RDD1) to a decoder (3) to form a third matrix (M3) of 384.times.560 pixel component values, interpolation filtering (4) the third matrix (M3) to form a fourth matrix (M4) of 768.times.560 pixel component values, forming the difference (5) between the first (M1) and fourth (M4) matrices to produce a fifth matrix (M5) of 768.times.560 difference values and encoding the fifth matrix (M5) as respective multi-bit and/or run length codes (RDD1) for storage on a compact disc (SM). Compatibility with known hardware (the CD-I standard `basecase` player) is obtained by encoding negative difference values using the quantization levels in the guard range (0-15) below black level (16, on a scale of zero to 255).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.