Image processing device having improved quality of its printed images

摘要

An image processing device includes a storage unit, a processing unit, and a memory. The storage unit stores a dither matrix. The memory has instructions stored thereon that, when executed by the processing unit, cause the processing unit to function as: an acquiring unit that is configured to acquire an image including a plurality of pixels, each pixel having a color value; an updating unit that is configured to update a color value of at least one pixel by adding a random number to the color value; and a thresholding unit that is configured to convert the updated color value into a binary value by using the dither matrix.

主权项

1. An image processing device comprising:
a storage unit that stores a dither matrix; a processing unit; and a memory storing instructions that, when executed by the processing unit, cause the processing unit to implement: acquiring a first image including a plurality of pixels, each pixel having a color value; determining whether or not the first image includes a specified area, the specified area containing at least part of the plurality of pixels, all pixels contained in the specified area representing colors whose color differences fall within a predetermined color difference; updating, when it is determined that the first image includes a specified area, the first image to generate a second image by adding a random number to a color value of each of pixels that are contained in the specified area, a color value of each of remaining pixels that are not contained in the specified area being unchanged; converting the color value of each of pixels that are contained in the second image into a binary value by using the dither matrix; detecting edges from the first image; dividing the first image into a plurality of image areas based on the detected edges; and finding a distribution of densities of pixels that are included in each of the plurality of image areas; wherein the determining determines, as the specified area, an image area whose distribution falls within a prescribed density range.