Selecting color states
AssigneeHewlett-Packard Development Company, L.P.
InventorsJavier Maestro Garcia, Jan Morovic, Peter Morovic
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Abstract
From a statistical distribution of different color states in an image subdivided in pixels, pixel color states are selected by performing comparisons between predetermined values and values associated to per-pixel state probabilities. Errors (based on drifts between selected color states and per-pixel state probabilities) are diffused to per-pixel state probabilities of subsequent pixels.
Claims20
A method comprising:
- defining, by a processor, a per-pixel vector of probabilities for a pixel of an image subdivided into pixels;
- defining, by the processor, a numerical interval for each probability of the vector of probabilities;
- and
- determining, by the processor, a color state of the pixel by comparing a predetermined value to the numerical interval for each probability of the vector of probabilities.
A system comprising a processor to:
- for a pixel of an image represented as a state probability, determine a numerical interval based on the state probability;
- compare a predetermined value to the numerical interval, the predetermined value selected from a matrix;
- choose the color state of the pixel on the basis of a result of the comparison;
- calculate a drift between the chosen color state and the state probability;
- and
- based on the drift, diffuse an error to the state probabilities of subsequent pixels.
A non-transitory machine-readable storage medium comprising machine-readable instructions which, when executed by a processor, cause the processor to:
- select an input from a statistical distribution of different color states for an image area subdivided in pixels, the statistical distribution a vector of Neugebauer Primary area coverage (NPac) values;
- for at least some pixels of the image area, perform a halftoning operation, wherein the halftoning operation causes the processor to:
- determine a numerical interval based on a value of the input;
- select a color state of a given pixel of the image area subdivided in pixels by comparing a predetermined value to the numerical interval, the color state a Neugebauer Primary (NP);
- calculate an error between the selected color state and a per-pixel state probability of the color state for the given pixel;
- diffuse the error to the vector of NPac values of a subsequent pixel;
- and
- use the vector of NPac values of the subsequent pixel to determine an NP for the subsequent pixel.
Dependencies are inferred from the claim text.