Patent ID: 9503749
Filing Date: 2016-11-22
CPC Classification: H04N

Claim Text:
1. An image encoding apparatus for encoding an image on a per block basis, the image encoding apparatus comprising: an encoding unit that encodes the image on a per block basis to generate the encoded image; a reconstruction unit that decodes the encoded image to generate a reconstructed image; a judging unit that judges whether a strong or a weak filter is to be applied to a boundary between a current block and a neighboring block adjacent to the current block; a calculating unit that calculates a linear combination of current samples in the current block and adjacent samples in the neighboring block, the current samples and the adjacent samples forming a line of samples; a shifting unit that shifts the linear combination right by a predetermined number of bits; a clipping unit that clips the shifted linear combination to generate a filtered sample of the filtered current block; and a filtering unit that filters three samples included in each of the current block and the neighboring block when the strong filter is to be applied, and filter one or two samples included in each of the current block and the neighboring block when the weak filter is to be applied, wherein (i) the shifted linear combination is clipped within a first range, for the strong filter, controlled by a first clipping parameter and (ii) the shifted linear combination is clipped within a second range, for the weak filter, controlled by a second clipping parameter regardless of any other condition, the first clipping parameter and the second clipping parameter depending on a strength of the boundary but the first range and the second range having a different range from each other, and the first clipping parameter and the second clipping parameter are respectively determined using a quantization parameter.