Image data processor and image data processing program storage medium

An image data processing program storage medium storing an image data processing program, which is executed in an information processing apparatus and causes the information processing apparatus to operate as an image data processor, the image data processor comprising:

• a data analyzing section that receives information specifying a reusable object that is an image object used repeatedly over a plurality of pages, information specifying a variable object that is an image object used once on a particular page, and page description data in page description language describing arrangement positions of image objects by each page formed by the reusable object and the variable object, and that generates object data having image objects specified by the page description data, and layout information having information of arrangement positions by each page of the image objects specified by the page description data;
• a rasterizing section that receives the object data generated in the data analyzing section and rasterizes each image object in the object data, thereby generates an object raster that is object data in a rasterized form of each image object;
• a pre-processing section that generates, based on the layout information generated in the data analyzing section, in regard to a group of reusable objects appearing in a range from a lowermost layer to a layer immediately before a variable object appears in the order of arranging image objects, one new object raster for each group of pages on which reusable objects constituting the group of reusable objects are identical and have same arrangement positions, the new object raster being object data in a rasterized form of a new reusable object generated by merging the reusable objects constituting the group of reusable objects, the pre-processing section also generating new layout information by replacing description of each of the reusable objects constituting the group of reusable objects in the layout information with description of a new reusable object corresponding to the group of reusable objects;
• and
• an assembling section that assembles the object raster generated in the rasterizing section and the new object raster generated in the pre-processing section by each page, based on the new layout information generated in the pre-processing section, thereby generating a page raster representing a rasterized image by each page.