摘要:
Methods and systems herein provide for color conversion. Such color conversion includes gamut mapping by determining a color gamut of an imaging device and receiving color data having color values external to the color gamut of the imaging device. The gamut mapping proceeds by determining a color region external to the color gamut and mapping the color values within the color region to the color gamut. Thereafter, the area of the color region is increased and the color values within the increased color region are mapped to the color gamut.
摘要:
A halftone method and apparatus provides a line screen frequency of N/2 for a printer resolution of N without negative print effects. A 300 lines per inch halftone screen for a 600 dpi printer may thus be created by alternating white and saturated colored lines when half of a given color component's pels are on. Empirical rules are used to create the screens based on how that printer creates consistent and reliable levels for each color component. These rules allow intermediate intensity values between white and full-on at each pel. Since the halftoning is done in the hardware just before printing, the print direction relative to the threshold matrix is known. No rotation capability is needed in the hardware. If an image needs to be rotated, it can be done previously to being sent to the hardware. Furthermore, because a pair of pels are turned on for the lightest values (or possibly with a one level difference between the first and second dots in the pair), the electronics are stressed less. Moreover, the drive will be at a lower frequency than the first dot in the traditional halftone cell, which remains isolated for many levels.
摘要:
Methods and systems herein provide for optimized color conversion. Such color conversion includes identifying color regions in the image data and identifying portions of the color regions that overlap. The color conversion also includes converting color values in the color regions to the color space of the output imaging device based on a plurality of numerical models. The color conversion further includes processing the overlapping portions of the color regions to remove abrupt transitions between the overlapping portions of the color regions. The numerical models may be generated based on human perception and a source of printer errors.
摘要:
Methods and systems herein provide for color conversion in the real domain from an input color space to an output color space using a color conversion table that includes color values defined in the output color space corresponding to color values in the input color space, a table of scaling factors, and a conversion engine operable to group the real domain image data into blocks of pixels. The conversion engine, for each block of pixels, converts a color value in the block of pixels from the input color space to the output color space according to the color conversion table, computes differences between the color value and color values of pixels in the block, scales the computed differences according to the table of scaling factors, and adds the scaled differences to the converted color values to convert the pixel color values to the output color space.
摘要:
A method and apparatus for converting a color representation of an image to a grayscale representation are disclosed. For a color image, a location of each color within a device-independent color space is initially determined. Then, a color difference of each color is determined by applying an appropriate perceptual-based color difference model according to its determined location within the device-independent color space. Next, the determined color difference of each color is normalized under a predetermined range. The normalized color differences are mapped to an output range of an output device.
摘要:
Provided are a method, system, and article of manufacture for converting image data in an input color space to an output color space in a transform domain. An input block of coefficients in an input color space is generated, wherein the input block includes a first type coefficient and a plurality of second type coefficients. The first type coefficient in the input block is converted to an output value in an output color space. The output value is used to determine a scaling factor for the second type coefficients. The scaling factor is applied to the second type coefficients to determine second type coefficients in the output color space. A component output block of coefficients in the output color space is formed from the output value for the first type coefficient and the determined second type coefficients in the output color space.
摘要:
Methods and apparatus for saving and re-using lookup tables (LUTs) used in generating color data objects in a presentation/printing system. A data object is generated by a device or application having an associated input ICC profile and is transferred to a presentation device having one or more associated output ICC profiles. The data object is converted from its input color space to a color space of the presentation device based on calculated LUTs. Once calculated, the LUTs are saved in a memory of the presentation device to be re-used for processing of a subsequent data object. The saved LUTs are indexed using the object ID (OID) of the ICC output profile used to calculate the LUT. A subsequent data object may specify use of the same ICC output profile such that the previously calculated LUT may be retrieve and re-used to obviate the calculation burden to recalculate the LUT.
摘要:
The Management of color presented at end point devices such as a display or printer is based on the implementation of a Color Management Resource (CR). A CMR is an architected resource stored accessibly to a print server or other processor that is used to carry all of the color management information required to render a print file, document, page, or data object.
摘要:
A nickel-rich wear resistant alloy comprises in weight % 0.5 to 2.5% C, 0.5 to 2% Si, up to 1% Mn, 20 to 30% Cr, S to 15% Mo, 5 to 15% W, 15 to 30% Fe, balance Ni. The alloy can include further alloying constituents such as up to 1.5% each of Ti, Al, Zr, Hf, Ta, V, Nb, Co, Cu, up to 0.5% B and up to 0.5% Mg plus Y. The alloy preferably has a microstructure containing predominantly eutectic reaction phases, fine intermetallic phases and precipitation carbides. For instance, the microstructure may contain Cr. Ni, W rich intermetallic phases and/or the microstructure may contain uniform lamellar type eutectic solidification structures. The alloy is useful as a valve seat insert for internal combustion engines such as diesel engines. For a valve seat insert containing up to 1.8% C the microstructure preferably is free of primary dendritic carbides. For a valve seat insert alloy containing over 1.8% C the microstructure preferably contains non-dendritic type primary carbides. For a valve seat insert containing up to 1.5% C the microstructure preferably includes solid solution phases encompassed by eutectic reaction products.
摘要:
A digital halftoning technique for controlling a spot function is disclosed. A method for generating a spot for use in halftoning according to the present invention includes defining a spot function that combines two functions selected to provide a predetermined spot shape for use in a halftone cell and scaling the spot function using a scaling function that varies according to a value of a first and second spot function ordinate. Asymmetric modulation of spot functions is used to control the touching of adjacent spots, and to change the shape of the spots with the gray region.