Image processing apparatus and its image processing method

An image processing apparatus, comprising:

• a storage section for storing image data;
• a storage managing section for managing the image data in the form of plural processing blocks that are arranged in a vertical direction and a horizontal direction, and storing at least part of the processing blocks in the storage section in such a manner that each processing block is accessible;
• a block data reading section for reading, as processing subject blocks, processing blocks that overlap with a rectangular area inclined with respect to the image data by a certain angle and in which at most three processing blocks are arranged in a reference direction which is a vertical direction or a horizontal direction, from the storage section for each band of processing blocks arranged in the reference direction;
• a rotated image buffering section for storing the read-out processing subject blocks, the rotated image buffering section having a capacity corresponding to three processing blocks for each band of processing blocks arranged in the reference direction;
• and
• a block rotating section for rotating the processing subject blocks that are read out by the block data reading section by a specified angle while maintaining positional relationships between the processing subject blocks, and storing rotated processing subject blocks in the rotated image buffering section.