Abstract: A method for locally adjusting the glossiness of a printed image includes printing an image onto a recording medium in multiple swaths and locally adjusting the ink volume for each swath. A printer for printing an image onto a recording medium includes a control unit configured to perform the method.

Abstract: A method for locally adjusting the glossiness of a printed image includes printing an image onto a recording medium in multiple swaths and locally adjusting the ink volume for each swath. A printer for printing an image onto a recording medium includes a control unit configured to perform the method.

Abstract: An image processing module for processing a digital M-level input image into a digital N-level output image is provided, wherein M>N and N>2, a level being indicative of a colorant density in a printing process. The module applies N-1 thresholds for determining an output level for each image element with an input level, wherein thresholds associated with a transition between two output levels are arranged in a threshold matrix, all N-1 threshold matrices being arranged in accordance with a single basic threshold matrix arrangement. The image processing module comprises threshold matrices, wherein the thresholds have been adjusted to compensate printed density variations except the thresholds associated with a transition between a first and a second level, which have not been adjusted in order to keep a number of colorant receiving print positions constant.

Abstract: A method for image processing a digital color image uses a single array of threshold values in a halftoning process if a total density value, which is found adding up the color density value for each of the process colors of a pixel, is lower than a predetermined density threshold. However, when the total density value exceeds the density threshold, the individual color density values are split in a basic part and an excess part, the basic parts adding up to the predetermined density threshold. In the halftoning process the basic parts still use the single array of threshold values, but the excess parts use uncorrelated arrays of threshold values that are associated with each individual process color. This provides for a balance between graininess at low color density and registration independent color rendering at high color density.

Abstract: A reproduction apparatus for printing a digital image includes a control unit and a print engine. The digital image is constituted of pixels, each having assigned a pixel value. The print engine includes print elements for ejecting an amount of marking material on a receiving material according to a pixel value. The reproduction apparatus includes a detector for detecting a failing print element and the control unit includes a derivation unit for deriving, before printing of the digital image for a print element, at least one array of pixel values to be printed by at least one other print element, upon detection of a failing of the print element by the detector. A merging unit is configured to merge at least one of the at least one array of pixel values with the digital image, upon detection of a failing print element, for creating a corrected digital image.

Abstract: A method of printing a spit pattern for an inkjet printer includes selecting a dot distance between dots of the spit pattern, selecting at least a sub-matrix of a dither matrix of entries arranged in rows and columns, constructing a bi-level bitmap of the same size as the sub-matrix, splitting each column of the bi-level bitmap which has more than one entry having a value of one into a number of columns such that each column of the number of columns comprises one entry having a value of one, removing each column of the bi-level bitmap which has no entry having a value of one, extracting the row and column number of each entry of the bi-level bitmap having a value of one, adapting the row number of each extracted entry in accordance with the dot distance, and printing the spit pattern.

Abstract: A method of printing a spit pattern for an inkjet printer includes selecting a dot distance between dots of the spit pattern, selecting at least a sub-matrix of a dither matrix of entries arranged in rows and columns, constructing a bi-level bitmap of the same size as the sub-matrix, splitting each column of the bi-level bitmap which has more than one entry having a value of one into a number of columns such that each column of the number of columns comprises one entry having a value of one, removing each column of the bi-level bitmap which has no entry having a value of one, extracting the row and column number of each entry of the bi-level bitmap having a value of one, adapting the row number of each extracted entry in accordance with the dot distance, and printing the spit pattern.

Abstract: A reproduction apparatus for printing a digital image includes a control unit and a print engine. The digital image is constituted of pixels, each having assigned a pixel value. The print engine includes print elements for ejecting an amount of marking material on a receiving material according to a pixel value. The reproduction apparatus includes a detector for detecting a failing print element and the control unit includes a derivation unit for deriving, before printing of the digital image for a print element, at least one array of pixel values to be printed by at least one other print element, upon detection of a failing of the print element by the detector. A merging unit is configured to merge at least one of the at least one array of pixel values with the digital image, upon detection of a failing print element, for creating a corrected digital image.

Abstract: A method for correction of a trapezoidal distortion of images in image processing for improved medium-image registration and also for controlling a printing device by performing the method for correction of a trapezoidal distortion of images in image processing for improved medium-image registration. Also included is a printing device comprising a controller for performing the present methods.

Abstract: A method is provided for processing digital multi-color images for the reproduction thereof on a color printing and/or copying system provided with a plurality of process colors defining a gamut. According to this method the gamut is divided into multiple non-overlapping sub-gamuts, each defined by three chromatic process colors. For each pixel of the digital multi-color image, a single corresponding sub-gamut is selected based on lightness differences between the respective chromatic process colors.

Abstract: A system and method are provided for processing digital multi-color images for the reproduction thereof on a color printing and/or copying device provided with a plurality of process colors defining a gamut. The system includes a color processing module, which divides the gamut into multiple sub-gamuts, each defined by three chromatic process colors, and which selects for each pixel of the digital multi-color image the corresponding sub-gamut. For each pixel it is judged whether or not to add a non-white achromatic process color or blue to the process colors defining the corresponding sub-gamut.

Abstract: A method for correction of a trapezoidal distortion of images in image processing for improved medium-image registration and also for controlling a printing device by performing the method for correction of a trapezoidal distortion of images in image processing for improved medium-image registration. Also included is a printing device comprising a controller for performing the present methods.

Abstract: A method and apparatus of converting a first color value as determined by first color co-ordinates in a color space defined by color parameters the first color co-ordinates being situated outside a boundary of a predetermined color range situated in the color space, to a second color value determined by second color co-ordinates in the color space, the second color co-ordinates being situated on said boundary of the color range. To this end, the method includes determining, in dependence on the distance of the first color co-ordinates from the boundary, an extended part of the boundary of the color range and establishing the second color co-ordinates on the basis of said extended part of the boundary. In one embodiment, the extended part of the boundary is determined by the boundary part situated between a first and second distance range from the first color co-ordinates and the second color co-ordinates are determined by the average of the color co-ordinates situated in that part of the boundary.