Patent · US Expired

Method of image filtering based on successive pixels

USRE40179E1 · kind E1 · reissue

2Cited by
20References
23Claims
0Family size

Assignee

Inventor

Key dates

Filing dateApr 11, 2005
Grant dateMar 25, 2008
Priority date
Expiry dateApr 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 selecting at least four successive pixels according to a position of a pixel to be filtered. The four successive pixels include the pixel to be filtered. At least one of the four successive pixels may be in a first block, and three of the four successive pixels may be in a secon…

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.