Patent ID: 7852943
Filing Date: 2010-12-14
Classification: H04N

Abstract:
1. A prediction image generation method for generating a prediction image from encoded data obtained by subjecting a video image to prediction encoding, the video image having a luminance component and first and second color difference components, the method comprising: receiving an input of encoded data obtained by encoding, for a to-be-decoded block, an index indicating (A) a reference image and (B) a combination factor comprising (a) a first weighting factor for the luminance component, (b) a second weighting factor for the first color difference component, (c) a third weighting factor for the second color difference component, (d) a first offset for the luminance component, (e) a second offset for the first color difference component, and (f) a third offset for the second color difference component; determining whether a decoding unit of the to-be-decoded block is a frame or a field; deriving, for the to-be-decoded block, the weighting factor factors and the offset offsets from the index; and generating a prediction image by multiplying the luminance component and first and second color difference components of the reference image, respectively, by the weighting factors and adding the offsets, respectively, to results of the multiplying; wherein the weighting factors and the offsets derived from the index when the decoding unit is the field are identical to the weighting factors and the offsets derived from the index when the decoding unit is the frame, which has a value obtained by performing a right arithmetic shift of one bit on a value of the index when the decoding unit is the field.