Resolution conversion using dither processing

摘要

An image processing apparatus includes a dither processing unit configured to perform dither processing on image data having a first resolution M by using a dither threshold value matrix and a resolution conversion unit configured to perform resolution conversion to convert the image data that is generated by the dither processing unit and which has the first resolution M into image data having a second resolution N lower than the first resolution M by using a filter, and the pixel of a growth center of the dither threshold value matrix and the center pixel of the processing using the filter coincide with each other.

主权项

1. An image processing apparatus comprising:
a memory storing instructions; and one or more processors which execute the instructions and cause the image processing apparatus to: perform dither processing on image data having a first resolution M by using a dither threshold value matrix; perform rotation processing on the image data that is generated by the dither processing unit and which has the first resolution M; and perform resolution conversion to convert the image data that is generated by the dither processing unit and which has the first resolution M into image data having a second resolution N lower than the first resolution M by using a filter, wherein the pixel of a growth center of the dither threshold value matrix and a center pixel in the processing using the filter coincide with each other; and derive coordinates of an arbitrary dither processing growth center point in the image on which the rotation processing has been performed, wherein in the case where the phase of the arbitrary dither processing growth center point and the phase of the center of the filter do not coincide with each other, the phase of the center of the filter is moved so as to coincide with the phase of the arbitrary dither processing growth center point based on the derived coordinates, and the resolution conversion is performed in accordance with the center of the filter after the phase thereof is moved so as to coincide with the phase of the growth center point.