Probabilistic pixel biasing in low area coverage
AssigneeXerox Corporation
InventorsStuart Schweid, Roger L. Triplett, John Newell
Life of this patent
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Abstract
Methods, apparatuses, devices, and systems are disclosed herein for upscaling an input image to a higher resolution while simultaneously converting the image data from a multi-drop state to a binary state. These systems and methods use a probabilistic combination of randomized and biased positioning of inkjet firings in order to yield perceptibly lower graininess in low-coverage areas of output prints without introducing new artefacts.
Claims18
1-6. (canceled)
A method of upscaling an input image from a lower resolution to a higher resolution, the method comprising:
- receiving a multi-state contone image data associated with the input image having a first resolution, wherein the multi-state contone image data includes a plurality of pixel values and an associated ink droplet size selected from two or more possible ink droplet sizes for each pixel of the multi-state contone image;
- determining a degree of isolation for each of the pixels of the multi-state contone image data;
- assigning a bias probability value to each pixel of the multi-state contone image data based on the degree of isolation corresponding to each pixel;
- converting each pixel value of the multi-state contone image data into a pattern of single-state inkjets activated in a plurality of N-by-M blocks of a binary output image data based on the bias probability value assigned to each pixel, wherein the single-state inkjets are configured to eject ink droplets of a single size;
- and
- outputting the binary output image data having a second resolution;
- wherein N and M are integers greater than or equal to 1;
- and
- wherein the second resolution is greater than the first resolution.
A printing system that upscales an input image from a lower resolution to a higher resolution, the system comprising:
- a multi-state contone image data associated with the input image having a first resolution, wherein the multi-state contone image data includes a plurality of pixel values and an associated ink droplet size selected from two or more possible ink droplet sizes for each pixel of the multi-state contone image
- one or more printheads configured to operate one or more inkjets to eject ink droplets of only one size to form pixels in ink images on a print medium;
- a processor operatively connected to the one or more printheads;
- and
- a memory operatively connected to the processor and containing programming instructions that are configured to instruct the processor to:
- receive from an image source the multi-state contone image data;
- determine a number of zero-pairs associated with one or more pixels of the multi-state contone image data by analyzing a plurality of pixels surrounding the one or more pixels;
- assign a bias probability value to each of the one or more pixels based on the number of zero-pairs associated with each of the one or more pixels;
- determine whether to bias each of the one or more pixels based on the bias probability value assigned to each of the one or more pixels;
- and
- convert each of the one or more pixels of the multi-state contone image data into a pattern of activated inkjets in one or more N-by-M blocks of the binary output image data, wherein N and M are integers greater than or equal to 2;
- output the binary output image data having a second resolution;
- wherein the pattern of activated inkjets corresponding to each of the one or more pixels is one of a biased pattern or a randomized pattern based on the determination of whether to bias each of the one or more pixels;
- and
- wherein the second resolution of the binary output image data is greater than the first resolution of the multi-state contone image data.
(canceled)
Dependencies are inferred from the claim text.