Patent ID: 9313499
Filing Date: 2016-04-12
CPC Classification: H04N

Claim Text:
1. An image decoding method for decoding an image, the image decoding method comprising: calculating a boundary strength between two adjacent blocks in the image; calculating a parameter determining an output range for each of a plurality of deblocking filters, based on a linear sum of the boundary strength and a quantization parameter; selecting one of the plurality of deblocking filters having different filter strengths, using one or more threshold values, the threshold values being determined based on the parameter; filtering the two blocks using the selected deblocking filter; and generating a reconstructed image including the filtered two blocks,. wherein the boundary strength is a first boundary strength when at least one of the two adjacent blocks includes a non-zero transform coefficient, and the boundary strength is a second boundary strength different from the first boundary strength when each of the two adjacent blocks does not include a non-zero transform coefficient, and the parameter has a variable value that is dependent on a value of the boundary strength.