To provide an image processor capable of performing deblocking processing within MB loop processing, reducing the number of times of loading and storing data and accelerating the entire processing further, its method and a program.

The image processor completes prediction processing and the deblocking processing in an MB unit in the signal processing of a video-codec for instance having a deblocking filter for noise reduction, and newly holds data at the lowest end of an adjacent upper MB and data at the rightmost end of an adjacent left MB in an operation unit 170 since pixel data before the deblocking processing are required for intra-prediction.