发明名称 |
Halftone screen |
摘要 |
A halftone screen may be used to transform a continuous tone image into a halftone image. Determining the halftone screen may include determining a first halftone tile for a first gray level, selecting pixel locations and increasing the intensity of pixels at the locations to activate the pixels to form a second halftone tile for a subsequent gray level. A filtered image may be generated from the second halftone tile, and pixels from the filtered image may be used to generate the halftone screen. |
申请公布号 |
US8934142(B2) |
申请公布日期 |
2015.01.13 |
申请号 |
US201313873483 |
申请日期 |
2013.04.30 |
申请人 |
Hewlett-Packard Indigo B.V. |
发明人 |
Kashti Tamar;Frank Tal;Haik Oren |
分类号 |
H04N1/405;H04N1/60 |
主分类号 |
H04N1/405 |
代理机构 |
Haseltine Lake LLP |
代理人 |
Haseltine Lake LLP ;Rogers Alex |
主权项 |
1. A method of determining a halftone screen for use in transforming a continuous tone image into a halftone image, the method comprising the steps of:
(a) determining a first halftone tile for a first gray level, the first halftone tile comprising a plurality of pixels locations; (b) selecting a plurality of the pixel locations to form a pixel pool; (c) selecting a subset of pixel locations from the pixel pool; (d) increasing intensity of pixels at the selected pixel locations to activate the pixels to form a second halftone tile for a subsequent gray level; (e) generating a filtered image of the second halftone tile; (f) selecting n activated pixels from the pixel pool having the highest density in the filtered image and n non-activated pixels from the pixel pool having the lowest density in the filtered image; (g) moving the intensity added from the n pixels having the highest density to the n pixels having the lower density to generate a new second halftone tile; (h) repeating steps (c) to (g) until a predetermined condition is met; (i) determining the halftone tile for the current gray level as the final second halftone tile; (j) removing the n selected pixels from the pixel pool; (k) repeating steps (c) to (j) until the pixel pool is empty for each subsequent gray level; and (l) determining a halftone screen comprising a plurality of the final second halftone tiles. |
地址 |
Maastricht NL |