An image is rendered on a display having a limited number of primary colors by (104) combining input data representing the color of a pixel to be rendered with error data to form modified input data, determining in a color space the simplex (208—typically a tetrahedron) enclosing the modified input data and the primary colors associated with the simplex, converting (210) the modified image data to barycentric coordinates based upon the primary colors associated with the simplex and (212) setting output data to the primary having the largest barycentric coordinate. calculating (214) the difference between the modified input data and the output data for the pixel, thus generating error data, applying (106) this error data to at least one later-rendered pixel, and applying the output data to the display and thus rendering the image on the display. Apparatus and computer-storage media for carrying out this process are also provided.

A system, method, and non-transitory computer readable medium are disclosed for mitigating dot placement errors for a given print job. The method includes processing tone values on a per pixel basis to determine whether to implement plane dependence. Plane independence is implemented if the tone value exceeds a predetermined threshold. The method may be performed on a pixel by pixel basis and/or a print object or region basis. Determining whether to implement plane dependence may involve de-asserting or partially de-asserting a plane dependence component of an executed half-toning instruction between sequentially processed color planes of a printing system.

Sharpness of image data in a low-frequency component, which is deceased by an image forming apparatus, is recovered and the recovered image data is converted into halftone image data. Halftone processing includes calculating edge intensity in a local region, dividing the local region into a first pixel group and a second pixel group based on a pixel value of each pixel, determining a distribution order of dots based on a pixel value of each pixel, a threshold value, and the edge intensity such that dots are likely to be distributed to the first pixel group and dots are unlikely to be distributed to the second pixel group, and determining an output value for each pixel in the local region by distributing dots to some pixels included in the local region as much as a number of dots to be output to the local region while referring to the distribution order.

Sharpness of image data in a low-frequency component, which is deceased by an image forming apparatus, is recovered and the recovered image data is converted into halftone image data. Halftone processing includes calculating edge intensity in a local region, dividing the local region into a first pixel group and a second pixel group based on a pixel value of each pixel, determining a distribution order of dots based on a pixel value of each pixel, a threshold value, and the edge intensity such that dots are likely to be distributed to the first pixel group and dots are unlikely to be distributed to the second pixel group, and determining an output value for each pixel in the local region by distributing dots to some pixels included in the local region as much as a number of dots to be output to the local region while referring to the distribution order.

We propose new methods for creating color varying prints with classical cyan, magenta, yellow inks on a metallic specularly reflecting or on a white diffusely reflecting substrate. We use a special cross-line halftone with optimized surface coverages of the inks to create cross-halftone prints whose colors change when rotating the print in-plane under specular reflection. These prints enable viewing at the same location a first image with a first set of colors and upon in-plane rotation of the print or displacement of the observer, a similar or a different image whose parts are colored with a different set of colors. Applications comprise counterfeit prevention, art, advertisement, decoration, exhibitions and surprising displays in amusement parks.

Methods and systems for the in-situ creation of a halftone noise screen layer by layer. Each layer produced is a white noise uniform distributed screen, statistically similar to one generated by a uniform noise function. The generation of each layer, however, is driven by a screen state which is an error based metric on the mean screen threshold. The set of screens produced are not independent of each other; adjacent layers are negatively correlated, while non-adjacent layers are completely uncorrelated. The result of this screen creation is that for any color the variation of coverage across the viewed surface is smaller than the variation produced by randomly generated screen planes. The algorithm is computationally inexpensive and eliminates the need to store multiple screens in memory.

Methods and systems for the in-situ creation of a halftone noise screen layer by layer. Each layer produced is a white noise uniform distributed screen, statistically similar to one generated by a uniform noise function. The generation of each layer, however, is driven by a screen state which is an error based metric on the mean screen threshold. The set of screens produced are not independent of each other; adjacent layers are negatively correlated, while non-adjacent layers are completely uncorrelated. The result of this screen creation is that for any color the variation of coverage across the viewed surface is smaller than the variation produced by randomly generated screen planes. The algorithm is computationally inexpensive and eliminates the need to store multiple screens in memory.

Systems and methods for replacing cells of an image based on some pre-determined metric are described herein. For example, systems and methods described herein may improve the functioning of a standard imaging system. For example, the systems and methods described herein may be used to post-process existing images in an imaging system based on one or more pre-determined metrics and improve the halftone images according to those pre-determined metrics.

Systems and methods for replacing cells of an image based on some pre-determined metric are described herein. For example, systems and methods described herein may improve the functioning of a standard imaging system. For example, the systems and methods described herein may be used to post-process existing images in an imaging system based on one or more pre-determined metrics and improve the halftone images according to those pre-determined metrics.

A method of screening a continuous-tone image is configured to produce an output image to be printed on a surface. The continuous-tone image comprises a plurality of pixels having respective corresponding intended print locations. The method includes selecting a first sequence comprising a subset of the plurality of intended print locations, the first sequence being selected based on properties of the plurality of intended print locations.

For each intended print location in the first sequence, the method also includes identifying the corresponding pixel in the continuous-tone image to obtain a second sequence for an error diffusion process comprising the identified corresponding pixels in the continuous-tone image.