An image processing apparatus includes an image processor that performs error diffusion processing by applying an error diffusion matrix to multi-valued image data having pixels two-dimensionally arranged, so as to convert the multi-valued image data into binary image data. The binarization unit applies an error diffusion matrix in which the diffusion coefficient of a pixel diagonal to a focused-on pixel is greater than those of other pixels.

A raster image processing system including a computer readable media storing digital information that includes information corresponding to an image, and instructions for performing raster image processing (RIP) using an over scan RIP technique on the image to generate a bitmap. Also included is a processor configured to RIP the image using the over scan RIP technique at a multiple of the desired output pixel resolution to produce a plurality of sub-pixels per output pixel. The processor is further configured to determine each image output pixel value based on the values set for the plurality of sub-pixels of each image pixel, by firstly comparing the values of the plurality of sub-pixels to each other and, and then secondly comparing the values of the plurality of sub-pixels to a set background value if needed. The processor then sets the output pixel value based upon that second comparison, and generates a bitmap.

A raster image processing system including a computer readable media storing digital information that includes information corresponding to an image, and instructions for performing raster image processing (RIP) using an over scan RIP technique on the image to generate a bitmap. Also included is a processor configured to RIP the image using the over scan RIP technique at a multiple of the desired output pixel resolution to produce a plurality of sub-pixels per output pixel. The processor is further configured to determine each image output pixel value based on the values set for the plurality of sub-pixels of each image pixel, by firstly comparing the values of the plurality of sub-pixels to each other and, and then secondly comparing the values of the plurality of sub-pixels to a set background value if needed. The processor then sets the output pixel value based upon that second comparison, and generates a bitmap.

An image processing apparatus includes an image processor that performs error diffusion processing by applying an error diffusion matrix to multi-valued image data having pixels two-dimensionally arranged, so as to convert the multi-valued image data into binary image data. The binarization unit applies an error diffusion matrix in which the diffusion coefficient of a pixel diagonal to a focused-on pixel is greater than those of other pixels.