Patent ID: 11962769
Assignee: SHARP KABUSHIKI KAISHA
Field: Audio-visual technology (Electrical engineering)
Classification: CPC H | IPC H

Claim 2:
3. An image decoding method for decoding an input image, generating a decoded image and filtering the decoded image, the image decoding method comprising
generating a luminance image by a process of scaling a luminance pixel value by using a histogram of decoded luminance, a process of a low-pass filter to a boundary of prediction unit or a transform unit so as to smooth pixels around the boundary and a process of categorizing pixels for the luminance image and a process of adding an offset according to a categorization;
applying an adaptive loop filter to the luminance image and a chrominance image, and output a filtered luminance image and a filtered chrominance image;
deriving an added value by using an equation (sum+64)>>7, wherein the sum is product sum of the luminance image and a cross component filter coefficient;
deriving a clipped value by clipping the added value within a range based on a bit depth; and
deriving a modified filtered chrominance image by adding the clipped value to the filtered chrominance image.