Patent ID: 8861029

Claim:
An image correction data generating apparatus that generates image correction data to perform gradation correction of an image for a gradation characteristic of a printing device, comprising: an image data acquiring unit configured (a1) to acquire image data of both a chart sheet on which a test chart is printed by the printing device and a predetermined reference chart from an external imaging device that photographs the chart sheet and the reference chart, and (a2) to acquire image data of a white sheet photographed by the external imaging device from the external imaging device; a shading correcting unit configured (b1) to generate shading correction data on the basis of a distribution of pixel values in the image data of the white sheet, and (b2) to perform shading correction for the image data of the chart sheet and the reference chart using the shading correction data; a projective transforming unit configured to perform a projective transformation for the image data of the chart sheet and the reference chart on the basis of markers on the chart sheet; a color value identifying unit configured to identify color values of patches in the test chart and color values of patches in the reference chart on the basis of the image data of the chart sheet and the reference chart after the shading correction and the projective transformation; and a correction data generating unit configured to generate image correction data on the basis of the identified color values of patches in the test chart and the identified color values of patches in the reference chart.