Patent ID: 8472042
Filing Date: 2013-06-25
Classification: G06K,H04N

Abstract:
1. An image forming apparatus which forms an image on a print medium based on print data described in a page description language, comprising: a conversion unit configured to convert inputted print data described in a page description language to intermediate data which is appropriate for rendering, and store the converted intermediate data into an intermediate data memory set in advance; a rendering unit configured to generate raster image data in accordance with the intermediate data stored in the intermediate data memory, and to generate attribute data for each pixel in the raster image data; an encoding/decoding unit configured to be able to set an encoding parameter for a tile, generate encoded data of each tile in accordance with the set encoding parameter, and store the generated encoded data into an encoded data memory set in advance, and configured to decode the encoded data stored in the encoded data memory; a determination unit configured to, in a case where an overflow occurs in the intermediate data memory while said conversion unit is converting to the intermediate data for a page of interest and storing the intermediate data into the intermediate data memory, determine whether or not the overflow is a first time or a second or further time for the page of interest; a fallback processing unit configured to, in a case where an overflow occurs in the intermediate data memory while said conversion unit is converting to the intermediate data for the page of interest and storing the intermediate data into the intermediate data memory, execute fallback processing in accordance with a determination result of said determination unit; and an image forming unit configured to, when rendering is completed based on the intermediate data for the page of interest, execute image forming processing based on image data obtained as a rendering result, wherein, (i) in a case where an overflow occurs in the intermediate data memory while said conversion unit is converting to the intermediate data for the page of interest and storing the intermediate data into the intermediate data memory, said fallback processing unit controls said rendering unit to perform rendering in accordance with the intermediate data which has already been stored in the intermediate data memory, (ii-1) in a case where the determination by said determination unit indicates that the overflow is a first time, said fallback processing unit performs tile division on the rendered image data in accordance with the attribute data of each object of the rendered image data, determines an encoding parameter for each tile, and controls said encoding/decoding unit to encode each tile in the rendered image data in accordance with the determined encoding parameter to store each encoded tile data into the encoded data memory; (ii-2) in a case where the determination by said determination unit indicates that the overflow is a second or further time, said fallback processing unit controls said encoding/decoding unit to decode each encoded tile data having already been stored in the encoded data memory due to a previous overflow, synthesizes the rendered image data with the decoded image data, performs the tile division based on attribute data of the synthesized image data, determines an encoding parameter for each tile, and controls said encoding/decoding unit to re-encode each tile in the synthesized image data in accordance with the determined encoding parameter to store each encoded tile data into the encoded data memory, and (iii) said fallback processing unit clears the intermediate data memory after each encoded tile data has been stored in the encoded data memory, and said conversion unit resumes conversion processing.