Filtering method and device in image processing

A filtering device, comprising:

• a dividing unit configured to divide a first filtering window into a plurality of blocks;
• a determining unit configured to determine a filtering window area according to relevance between a central block and other non-central blocks in the plurality of blocks;
• and
• a filtering unit configured to perform filtering processing on an image in the determined filtering window area;
• wherein the determining unit comprises:
• a calculating module configured to calculate a relevance parameter of each of the plurality of blocks;
• a comparing module configured to compare a relevance parameter of each of the non-central blocks in a predetermined direction of the central block with a relevance parameter of the central block according to the result of calculation of the calculating module;
• and
• a determining module configured to determine whether the non-central blocks are related to the central block according to the result of comparison of the comparing module, and excluding non-central blocks of rows and/or columns where boundary blocks are located and their peripheral non-central blocks from a range of the filtering window area by taking non-central blocks unrelated to the central block as the boundary blocks.