IMAGE ENCODING APPARATUS, IMAGE ENCODING METHOD AND PROGRAM THEREOF

摘要

An object to be attained by the present invention is to provide an image encoding technology for reducing the number of transform operations required in SATD calculation in intra-frame predictive direction estimation using a method involving no image quality degeneration. An image encoding apparatus of the present invention transforms an input pixel block having NxM pixels into N×M transform coefficients; locally transforms an intra-frame predicted pixel block having N×M pixels based on the property of intra-frame prediction; and detects the best intra-frame predictive direction by comparing transform coefficients of the transformed input pixel block with transform coefficients of an intra-frame predicted pixel block in each intra-frame predictive direction.