Method of filtering an image
USRE40178E1 · kind E1 · reissue
Assignee
Inventor
Key dates
| Filing date | Apr 11, 2005 |
| Grant date | Mar 25, 2008 |
| Priority date | — |
| Expiry date | Apr 11, 2025 |
Classification
- Technology area (CPC —)General
Abstract
A method and apparatus to remove a block effect and a ring effect appearing in a compression-coded image is disclosed. The present invention is especially applicable to an image compression-coded at a low bit rate. In particular, the present invention includes a variety of masks for the removal of the block/ring effect. Thus, one mask is select for a pixel to be filtered. Moreover, candidate pixels to be averaged with the pixel to be filtered is selected from the pixels of the selected mask to better maintain the details of the image, and a weight is applied to improve the calculation speed of the averaging operation. More particularly, the masks according to the present invention have longer tabs toward adjacent blocks at boundaries of the given block to remove the block and ring effect. In the method, a pixel of an image is filtered according to a filtering methodology. The filtering methodology includes more than one comparison, and each comparison compares a respective determined value and a respective threshold. At least one of the respective thresholds may be based on quantization information of at least a portion of the image including the pixel. Each respective determined …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.