Abstract: Density of each pixel is specified from a test pattern for measurement of density distribution, a density profile indicating distribution of the specified density for each pixel is acquired, and a pixel region including a “nozzle of interest” having a certain density difference or more from surrounding pixels and pixels on both sides thereof is extracted as a nozzle region of interest from the acquired density profile. Filters B to E, other than a filter A to be applied for density smoothing processing of pixels that do not belong to the nozzle region of interest, are applied for the density smoothing processing of the pixels in the nozzle region of interest, to generate a profile of a density correction value for eliminating a density difference between respective pixels based on the density profile after the smoothing processing.

Abstract: Density of each pixel is specified from a test pattern for measurement of density distribution, a density profile indicating distribution of the specified density for each pixel is acquired, and a pixel region including a “nozzle of interest” having a certain density difference or more from surrounding pixels and pixels on both sides thereof is extracted as a nozzle region of interest from the acquired density profile. Filters B to E, other than a filter A to be applied for density smoothing processing of pixels that do not belong to the nozzle region of interest, are applied for the density smoothing processing of the pixels in the nozzle region of interest, to generate a profile of a density correction value for eliminating a density difference between respective pixels based on the density profile after the smoothing processing.

Abstract: A controller of an inkjet printer: calculates second density correction values for respective nozzles arranged in a predetermined direction to print a second line of an image data, by using gray-level values of pixels in the second line of the image data corresponding to the respective nozzles and first density correction values for the respective nozzles to print a first line of the image data printed immediately prior to the second line; and corrects the gray-level values of the pixels in the second line of the image data corresponding to the respective nozzles, by using the calculated second density correction values.

Abstract: A controller of an inkjet printer: calculates second density correction values for respective nozzles arranged in a predetermined direction to print a second line of an image data, by using gray-level values of pixels in the second line of the image data corresponding to the respective nozzles and first density correction values for the respective nozzles to print a first line of the image data printed immediately prior to the second line; and corrects the gray-level values of the pixels in the second line of the image data corresponding to the respective nozzles, by using the calculated second density correction values.