Patent ID: 8094954

Claim:
An image processing apparatus that converts multilevel input image data into multilevel output image data having fewer levels than the multilevel input image data and used in an image output device, comprising: a modifying device that modifies an input level value of a subject pixel in the input image data with use of an error value generated by a level conversion as to a pixel close to the subject pixel and calculates a modified level value of the subject pixel; a determining device that determines an output level value of the subject pixel in the output image data based on a comparison between the modified level value of the subject pixel and a threshold value; an error value calculating device that calculates the error value for the subject pixel from a difference between the output level value of the subject pixel and the modified level value of the subject pixel; a mode setting device that adjusts the image output device to operate in one of a plurality of image output modes each of which outputs output image data at a different resolution; and an output level value setting device that sets the output level value used by the error value calculating device to a value corresponding to the one of the plurality of image output modes set by the mode setting device, wherein: when a predetermined image output mode is set by the mode setting device, the output level value setting device sets the output level value used by the error value calculating device to a value greater than the output level value when another of the plurality of image output modes is set, and the predetermined image output mode is an image output mode for outputting output image data having a highest resolution.