Continuous-tone image compression
US5455874A · kind A · utility
75Cited by
46References
24Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Sep 20, 1993 |
| Grant date | Oct 3, 1995 |
| Priority date | — |
| Expiry date | Sep 20, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N19/146
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Continuous tone images, represented by original data files are compressed by (1) transforming by a lapped orthogonal transform the original file of data to generate a transform file of coefficients, (2) quantizing the transform coefficients, and (3) coding the quantized values to generate a compressed data file, the lapped orthogonal transform being arranged to compute all transform coefficients by means only of bit shifts, negations, and adds. In another aspect, the quantization and coding are performed on groups of transformed coefficients.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.