Patent ID: 8675976

Claim:
An image information encoding apparatus, comprising: a processor; an intra-image prediction unit configured by the processor to: perform intra prediction of a received image corresponding to a chroma signal in an intra DC prediction mode; and generate, when the chroma signal format has a 4:4:4 format, a prediction image corresponding to the chroma signal by: dividing a block of 16×16 pixels into four unit blocks of 8×8 pixels arranged in longitudinal and lateral directions within the block of 16×16 pixels; and calculating, for each of the unit blocks of 8×8 pixels, mean pixel values using first pixel values of vertical pixels disposed adjacent to a longitudinal edge of the block of 16×16 pixels and second pixel values of horizontal pixels disposed adjacent to a lateral edge of the block of 16×16 pixels; a transformation unit configured by the processor to generate transform coefficients corresponding to a transformation of components of a difference signal, the difference signal representing differences between the prediction image and the received image; and a quantization unit configured by the processor to quantize the transform coefficients using a quantization scaling factor, the quantization scaling factor being determined in accordance with a scaling factor corresponding to an application of the transformation to a 4×4 chroma DC block.