Method and system for decoding encoded images and reducing the size of said images
US8045810B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 28, 2008 |
| Grant date | Oct 25, 2011 |
| Priority date | — |
| Expiry date | Aug 20, 2030 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N19/80
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method and system for reducing the number of mathematical operations required in the JPEG decoding process without substantially impacting the quality of the image displayed is disclosed. Embodiments provide an efficient JPEG decoding process for the purposes of displaying an image on a display smaller than the source image, for example, the screen of a handheld device. According to one aspect of the invention, this is accomplished by reducing the amount of processing required for dequantization and inverse DCT (IDCT) by effectively reducing the size of the image in the quantized, DCT domain prior to dequantization and IDCT. This can be done, for example, by discarding unnecessary DCT index rows and columns prior to dequantization and IDCT. In one embodiment, columns from the right, and rows from the bottom are discarded such that only the top left portion of the block of quantized, and DCT coefficients are processed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.