Patent ID: 8130838

Claim:
An encoder for performing motion compensated inter-picture predictive coding on moving picture data including image data of multiple pictures, the encoder comprising: an accumulated error detecting section for detecting, for each of multiple prediction modes, an accumulated error between a block to be encoded, which is included in image data to be encoded, and a reference block of reference picture data to be used in each said prediction mode when the block to be encoded is encoded; a transformation section for transforming the accumulated error in each said prediction mode, which has been detected by the accumulated error detecting section, into an estimated code size in the prediction mode using transformation data; a determining section for selecting one of the multiple prediction modes according to an estimated value based on the estimated code size in each said prediction mode that has been transformed by the transformation section; and an encoding section for encoding the block to be encoded of the image data to be encoded in the prediction mode selected, wherein the transformation data is determined by a quantization scale for use when the block to be encoded is quantized and another quantization scale that has been used at a different time from the former quantization scale, and further comprising a motion vector detecting section for detecting, for each of multiple prediction modes, a motion vector between a block to be encoded, which is included in image data to be encoded, and a reference block of reference picture data to be used in each said prediction mode when the block to be encoded is encoded; and an estimating section for calculating an estimated value for each said prediction mode based on the estimated code size that has been transformed by the transformation section for each said prediction mode and on the motion vector that has been detected by the motion vector detecting section for each said prediction mode, wherein the determining section selects one of the multiple prediction modes according to the estimated value that has been calculated by the estimating section for each said prediction mode.