Abstract: In order to improve print image quality, attribute information is generated for each pixel of a bitmap image generated according to a drawing command, and the bitmap image and attribute information are written in a memory. However, when this is done, data amount to be written in the memory increases, and the rasterize processing speed lowers. Hence, a display list is generated by interpreting PDL data, a bitmap image and attribute information of each pixel are rasterized based on the display list, and the bitmap image and attribute information are written in the memory. In this case, a black attribute is written in attribute information of an object filled with black, and the color value of that object is not written in the bitmap image.

Abstract: An image forming apparatus specifies as a blank area an area where a drawing object different from a latent image and a copy-forgery-inhibited pattern background image is removed from a copy-forgery-inhibited pattern image in a first page when printing is instructed, and lays out a drawing object of a second page in the specified blank area.

Abstract: In order to improve print image quality, attribute information is generated for each pixel of a bitmap image generated according to a drawing command, and the bitmap image and attribute information are written in a memory. However, when this is done, data amount to be written in the memory increases, and the rasterize processing speed lowers. Hence, a display list is generated by interpreting PDL data, a bitmap image and attribute information of each pixel are rasterized based on the display list, and the bitmap image and attribute information are written in the memory. In this case, a black attribute is written in attribute information of an object filled with black, and the color value of that object is not written in the bitmap image.

Abstract: An image forming apparatus for rendering graphics objects in a frame memory, which includes a line memory for storing dot image data for each scan line of the graphics objects, a deciding unit that decides a position of a difference pixel having different values of corresponding pixels between the scan line stored in the line memory and a target scan line immediately thereafter, and a difference updating unit that, of the dot image data stored in the line memory, updates a value of the difference pixel decided by the deciding unit to the value of the pixel in the target scan line.