Patent ID: 11909939
Assignee: TOPPAN PRINTING CO., LTD.
Field: Audio-visual technology (Electrical engineering)
Classification: CPC H  B | IPC H

Claim 13:
14. A method of generating image data, comprising:
acquiring first image data represented in two or more colors, the first image data comprises a plurality of pixels, wherein said acquiring comprises acquiring for each pixel of the plurality of pixels of the first image data, a tone value for each of the two or more colors; and
based on the first image data, generating second image data comprising a plurality of pixels, wherein each pixel of the plurality of pixels of the second image data has a binarized tone value for each of the two or more colors, wherein
the generating the second image data includes:
selecting a first pixel from the plurality of pixels of the first image data;
performing a first comparison of the tone value of the first pixel with a first threshold;
if the first comparison shows that the tone value of the first pixel is greater than the first threshold, binarizing the tone value of the first pixel by a first binarization process;
if the first comparison shows that the tone value of the first pixel is less or equal than the first threshold, performing a second comparison of the tone value of the first pixel with a second threshold smaller than the first threshold;
if the second comparison shows that the tone value of the second pixel is smaller than the second threshold, binarizing the tone value of the first pixel by a second binarization process different from the first binarization process, and
if the second comparison shows that the tone value of the second pixel is equal or greater than the second threshold, binarizing the tone value of the first pixel by a third binarization process different from the first binarization process and the second binarization process, and wherein the method further comprises
before generation of the second image data, setting, for each color of the two or more colors, a magnitude of the first threshold and a magnitude of the second threshold to be used in generation of the second image, wherein
said setting the magnitude of the first threshold and the magnitude of the second threshold to be used in generation of the second image data include:
acquiring third image data corresponding to part of the first image data, the third image data comprises a plurality of pixels;
for each combination of a plurality of magnitude combinations for the first threshold and of the second threshold, binarizing a tone value of each pixel of the plurality of pixels of the third image data by any of the first binarization process, the second binarization process, and the third binarization process to generate fourth image data comprising a plurality of pixels, each pixel of the plurality of pixels of the fourth image data having a binarized tone value; and
setting the magnitude of the first threshold and the magnitude of the second threshold to be used in generation of the second image data to be a value of the first threshold and a value of the second threshold in a combination of the plurality of magnitude combinations, in which a summed value of differences in pixel between the third image data and the fourth image data is minimized.