1. An image processing method where each of the pixel blocks composing a picture is divided into a plurality of sub-blocks and these plurality of sub-blocks are coded in sequence while referring to context information indicating at least a prediction direction in the picture or between the picture and an adjacent picture, comprising: reading the prediction direction from the context information; and coding each of said sub-blocks while adaptively changing a coding order of remaining sub-blocks that have not been coded based on the prediction direction.