Methods for calculating video inverse transform
US8194988B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 20, 2008 |
| Grant date | Jun 5, 2012 |
| Priority date | — |
| Expiry date | Apr 5, 2031 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N19/60
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Inverse transforms used in video and image compression/decompression, such as DCT/IDCT used in MPEG-2 and MPEG-4, or the integer transforms used in H.264, are usually calculated with fast algorithms, which only take advantage of the symmetry existing in the transform matrix but ignores the peculiarities in the input data. While these kind of fast algorithms can apply to both forward and inverse transforms, they tend to be inefficient in calculating inverse transforms. In inverse transforms, most of the coefficients become zero after quantization, this invention takes advantage of this fact to further simplify the general fast algorithm and speed up the calculation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.