Methods to print N-tone images with multi-leveling techniques
AssigneeHewlett-Packard Company
InventorQian Lin
Life of this patent
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Abstract
Generating a N-tone image from a grey scale image with a number of multi-level dither matrices. Both images have many pixels, with each pixel in the grey scale image having a grey level that is within a maximum and a minimum levels, and with each pixel in the N-tone image having a level that is one of N levels with N bigger than two. The method includes the step of determining the level of each pixel in the N-tone image based on the levels of its corresponding pixel in the grey scale image, and an original dither matrix, the separations between adjacent levels in the N levels are not uniform. After the determination process, every pixel in the N-tone image is modelled to represent its level. Based on the modelling, the N-tone image is printed.
Claims16
A method of generating N-intensity-tone image from a grey scale image, both images having a plurality of pixels, each pixel in the grey scale image having a grey level that is within a maximum and a minimum levels, and each pixel in the N-intensity-tone image having a grey level that is one of N intensity levels with N bigger than two, the method comprising the steps of:
- determining the intensity level of each pixel in the N-intensity-tone image based on the level of its corresponding pixel in the grey scale image and based on an original dither matrix, the number of grey levels between adjacent levels in the N intensity levels being not constant;
- modeling the intensity level of every pixel in the N-intensity-tone image;
- and
- printing the N-intensity-tone image with a printer by printing the intensity level of each pixel based on the modeling;
- such that:
- the printer prints the intensity level of each pixel by controlling a pulse with a pulse width;
- and
- the pulse width of one intensity level is different from the pulse width of at least one other intensity level.
A method of generating N-intensity-tone image from a grey scale image based on an original dither matrix and a plurality of standard matrices, the matrices and the images having a plurality of pixels, each pixel in the grey scale image having a grey Ievel that is within a maximum and a minimum levels, and each pixel in the N-intensity-tone image having one of N levels with N bigger than two, the number of grey levels between adjacent levels in the N intensity levels being not constant, the method comprising the steps of:
- determining the intensity level of each pixel in the N-intensity-tone image by comparing the level of its corresponding pixel in the grey scale image to the corresponding pixel in a special dither matrix, the special dither matrix being dependent on (a) the N intensity levels, (b) the original dither matrix and (c) modeling with sub-pixels to generate N intensity levels;
- and printing the N-intensity-tone image with a printer by printing the intensity level of each pixel according to its determined intensity level;
- such that:
- the printer prints the intensity level of each pixel by controlling a pulse with a pulse width;
- and
- the pulse width of one intensity level is different from the pulse width of at least one other intensity level.
Dependencies are inferred from the claim text.