Patent ID: 8509547
Filing Date: 2013-08-13
Classification: H04N

Abstract:
1. A scan conversion apparatus which scans a block formed from N data of a two-dimensional array and sorts the data into one-dimensional array data, the apparatus comprising: a holding unit which holds scan order information which is determined based on an appearance frequency of significant data at each position in a block scanned in the past and indicates a scan order in the block; a first scan conversion unit which scans N data which form a first block, in an order indicated by the scan order information, and outputs the N data as one-dimensional array data; an update unit which, when data at a position A in a block is significant data during scanning by said first scan conversion unit, updates an appearance frequency corresponding to the position A; a swapping unit which, when an appearance frequency (of significant data) at a position B (in the block) corresponding to a scan turn immediately before the position A is smaller than the appearance frequency (of significant data) at the position A after update by said update unit, swaps the scan orders of the position A and position B that are indicated by the scan order information; and a second scan conversion unit which reads out N data which form a second block following the first block, in an order indicated by the scan order information, and outputs the N data as one-dimensional array data, wherein said second scan conversion unit starts scanning the second block before completion of scanning the first block by said first scan conversion unit, and when said first scan conversion unit scans I-th data of the first block, said second scan conversion unit scans (I-K)th (K is at least 2) data of the second block at earliest in order to reflect a swapping result by said swapping unit along with scanning of the first block by said first scan conversion unit.