Abstract: A method for fabricating a flexographic printing plate for printing image patterns including one or more uniform image regions includes defining a repeating tile having a plurality of different feature shapes positioned in a pattern of pseudo-random feature locations. A plate formation pattern corresponding to the image pattern is determined wherein the repeating tile is applied in a tiled arrangement to the uniform image regions. The plate formation pattern is used to form a flexographic printing plate, wherein regions of the flexographic printing plate corresponding to the uniform image regions of the image pattern include a pattern of raised features in positions corresponding to the feature positions in the repeating tile.

Abstract: A method of computing swath data in response to a digital image having a plurality of rows and columns of pixels, each pixel having a multitone code vaule, the swath data suitable for commanding an inkjet printer containing at least one printed having plurality of nozzles, wherein the inkjet printer is capable of ejecting ink drops in response to the swath data.

Abstract: A method of computing swath data in response to a digital image having a plurality of rows and columns of pixels, each pixel having a multitone code vaule, the swath data suitable for commanding an inkjet printer containing at least one printed having plurality of nozzles, wherein the inkjet printer is capable of ejecting ink drops in response to the swath data.

Abstract: A method for modifying an input digital image having one or more color channels, each color channel having an (x,y) array of image pixel values, to form a modified digital image so that when the modified digital image is used to produce a printed image on an inkjet printer there are reduced ink bleed artifacts.

Abstract: Method for building color transforms for color imaging devices having concave color gamut regions, including forming a device model that relates device control signals for a color imaging device to corresponding device-independent color values in a device-independent color space; forming a device color gamut representing the set of colors in the device-independent color space that are producible by the color imaging device; and forming a convex color gamut by fitting a convex hull to the device color gamut. The method further includes forming an expanded device model that relates device control signals for the color imaging device to expanded device-independent color values in the device-independent color space, such that the expanded device-independent color values fill the convex color gamut; and building a color transform that relates input device-independent color values to corresponding device control signals for the color imaging device using the expanded device model.

Abstract: A method for determining colorant control values for a color imaging device having four or more colorants is disclosed. The method includes defining a color mapping for a set of paths through a three-channel color space, defining a color mapping function for the three-channel color space relating the three-channel color space values to colorant control values for the four or more colorants of the color imaging device by interpolating between the color mapping defined for the set of paths, forming a forward three-channel color model relating the three-channel color space values to device-independent color values, inverting the forward three-channel color model to determine an inverse three-channel color model relating the device-independent color values to the three-channel color space values, and combining the inverse three-channel color model and the color mapping function to determine an inverse device color model.

Abstract: A method for forming a modified digital image by modifying an input digital image having a black input color channel corresponding to a black colorant and one or more additional input color channels corresponding to additional colorants, each color channel having an (x,y) array of image pixel values, to form a modified digital image having one or more modified color channels, said modified digital image being suitable for producing a printed image having reduced ink bleed artifacts on an inkjet printer using the black and additional colorants includes forming a filtered black color channel from the black input color channel using a convolution operation, and forming the modified digital image by modifying image pixel values in one or more of the additional input color channels in response to the corresponding image pixel values of the filtered black color channel.

Abstract: In an image enhancement method, a regular enhancement function and an aggressiveness parameter are computed using characteristics of a digital image. A first, relatively slow enhancement algorithm is applied to the digital image using the regular enhancement function, when an aggressiveness parameter is in a predetermined high range. A second, relatively fast enhancement algorithm is applied to the digital image using the regular enhancement function, when an aggressiveness parameter is in a predetermined low range. A modified enhancement function is calculated using characteristics of the digital image and is used with a second, relatively fast enhancement algorithm, when the aggressiveness parameter is in a predetermined medium range.

Abstract: A method for determining a sharpness predictor for an input digital image includes determining one or more image metrics by analyzing the input digital image; and determining the sharpness predictor from the one or more image metrics.

Abstract: A method for determining a set of n-dimensional colorant control signals that map to a point P in an m-dimensional color space where n>m, including determining a forward device model that maps n-dimensional colorant control signals to m-dimensional color space signals; determining a set of n-dimensional colorant control signal simplexes that span a domain of the forward device model; and determining a set of range space simplexes in the m-dimensional color space corresponding to the set of n-dimensional colorant control space signal simplexes by mapping the vertices of the n-dimensional colorant control signal simplexes into the m-dimensional color space using the forward device model. The method also includes specifying a point P in the m-dimensional color space; and determining the set of n-dimensional colorant control signals that map to the point P in the m-dimensional color space, by performing m sequential slicing processes through the set of range space simplexes.

Abstract: A method for multi-level halftoning an input digital image to form an output digital image which includes a multi-level error diffusion halftoning process incorporating periodic dither signals whose amplitudes are adjusted as a function of the error-diffusion texture characteristics.

Abstract: A method for multi-toning an input digital image having input pixels with two or more color channels to form an output digital image having modified output levels. The method includes producing an error signal for each color channel, combining the error signals to produce a combined error signal, sorting the error signals to produce a set of sorted error signals, and determining modified output levels responsive to the set of sorted error signals and the combined error signal.

Abstract: A method is described for applying an image enhancement algorithm to input digital images represented in different input color spaces including identifying the input color space of an input digital image, and applying a color space transformation to the input digital image represented in the input color space to form a corresponding input digital image in a reference color space. The method also includes adjusting one or more algorithm parameters of the image enhancement algorithm in response to the identified input color space, and applying the image enhancement algorithm with the one or more adjusted algorithm parameters to the corresponding input digital image in the reference color space to produce an enhanced digital image in the reference color space.

Abstract: A method for reconstructing an extended color gamut digital image from a limited color gamut digital image includes transforming the limited color gamut digital image in the particular limited color gamut color space to a reference color space forming a limited color gamut digital image in a reference color space; providing a modified inverse color adjustment function which, when such function operates on the limited color gamut digital image in the reference color space, produces the reconstructed extended color gamut digital image having reduced highlight color saturation for highlight color values when compared with corresponding color values of the initial extended color gamut image; and operating on the limited color gamut digital image in the reference color space with the modified inverse color adjustment function to form the reconstructed extended color gamut digital image having reduced levels of color contouring and quantization artifacts.

Abstract: Disclosed is a method for converting an input digital color image having a set of possible input colors to an output digital color image having a set of palette colors, the number of palette colors being less than the number of possible input colors, wherein the set of palette colors is determined based on the distribution of colors in the input digital image boosted by a distribution of important colors contained in the input digital image.

Abstract: In order to stabilize the coupling angle, at which light is coupled into and out of an optical waveguide of an integrated optical circuit or the like, with changes in wavelength of the light (to achromatize the coupling angle characteristics of the waveguide input/output coupler) a hybrid prism/grating coupler is used. The grating produces achromatic coupling over a range which can be as large as 200 nanometers (nm) for typical waveguide materials by compensating for the dispersion due to the change in the effective mode index of the waveguide and the prism with variations in wavelength.

Abstract: A lens in a waveguide of an integrated optical circuit is achromatized (corrected for chromatic dispersion which varies the focal length of the lens with wavelength) by forming the lens as a hybrid mode-index/diffractive doublet. The chromatic dispersion of the diffractive element cancels the dispersion of the refractive element (the mode-index lens) such that the derivative of the focal length goes to zero at the design wavelength, and significantly reduces chromatic dispersion over a substantial wavelength range. For example, a 10 mm focal length, F/5 hybrid mode-index/diffractive lens may be provided with a useable wavelength range of approximately 80 mm for typical waveguide materials.