Patent ID: 8509532
Filing Date: 2013-08-13
Classification: H04N

Abstract:
1. An image processing apparatus comprising: a tile division unit configured to divide image data, in which a pixel value of each pixel includes color data and attribute data, into tiles each including a predetermined number of pixels; a block division unit configured to divide each of the tiles, that are divided by said tile division unit, into blocks each having a size of 2×2 pixels; a specification unit configured to sequentially determine, as a processing object, each of the blocks divided by said block division unit, and to compare pixel values of respective pixels in the block that is the processing object, thereby specifying a pattern flag indicating an arrangement pattern of pixel values included in each of the blocks; an extraction unit configured to extract first color data and first attribute data from a pixel value corresponding to a pixel at a predefined position in each of the blocks, and further to extract, from a block for which it is determined that the number of pixel values included in the block is one of 2 to 4, second color data to fourth color data and second attribute data to fourth attribute data corresponding to a second pixel value to a fourth pixel value corresponding to the arrangement pattern defined in the specified pattern flag; a first holding unit configured to hold, in a memory, the pattern flag of each of the blocks, that is specified by said specification unit, the first color data extracted by said extraction unit, the second color data to fourth color data extracted by said extraction unit, the first attribute data extracted by said extraction unit, and the second attribute data to fourth attribute data extracted by said extraction unit; a first determination unit configured to determine whether attribute data of all pixels included in the tile are identical; and a deletion unit configured, if said first determination unit determines that the attribute data of all the pixels included in the tile are identical, to perform control to delete the first attribute data and the second attribute data to fourth attribute data, that are held in said first holding unit, and to store, in header information, information indicating that the attribute data in the tile are identical and information of the attribute data determined to be identical.