Abstract: A method (and system) for changing spatial resolution of an image includes systematically creating an image scaling look-up table including at least one pixel replacement pattern and applying a scaling algorithm to modify the image using the image scaling look-up table, thereby allowing a user to scale binary images with easy control of dot gain, output bit depth and other printer parameters.

Abstract: Provided are a method, system, and program for generating threshold values in a dither matrix. A dither matrix of threshold values is generated.

Abstract: A method (and system) of multi-bit halftoning includes comparing values of an image to threshold values of a halftone threshold matrix, and generating output values that provide a greater than minimum level of contrast.

Abstract: A method and system for generating halftone tables, using a spot function, subdivides the pixels within the halftone cell of a halftone matrix into a plurality of sub-pixels, determines the value of the spot function corresponding to the position of each of the sub-pixels within the halftone matrix, repeats the subdividing and determining for all of the sub-pixels in the halftone matrix, ranks the values for the entire halftone matrix, normalizes the ranked values, generates a cumulative histogram based upon the normalized values, and stores the cumulative histogram as a halftone table.

Abstract: A multiple beam printer system having N laser beams receives print job information from a print host. A rendering application uses a threshold array to generate halftone image data from the print job. The threshold array is defined based on a spot function. The defined screen is non-orthogonal and includes Y pels in a direction that is perpendicular to a scanning direction of the laser beams where Y is an integer multiple of N. A distance between screen dots in pels is preferably equal to an integer multiple of N. The screen dot may be defined by a supercell encompassing two screen dots and having an odd number of pels in a direction that is parallel to the scanning direction. The spot function may include a snap feature that snaps a screen dot to the nearest printer grid pel. The spot function may include scaling to compensate for the distortion of the non-orthogonal screen dot.

Abstract: Techniques for generating dither masks are provided. A dither mask is generated by selecting a sequence of at least three original patterns comprising pixels of at least one of a first color and a second color. At least two patterns are interpolated to generate interpolated patterns in the sequence between the at least three original patterns. If a pattern having at least one specified characteristic exists in the sequence, the steps of interpolating between at least two patterns, and determining if a pattern having at least one specified characteristic exists in the sequence, are repeated. The interpolation is between at least one pattern from each side of the pattern having at least one specified characteristic in the sequence.

Abstract: A method, computer program product and system for detecting and compensating for color misregistration. A black/white edge or a solid color edge on a target may be scanned. A black/white edge may refer to a black image, e.g., black text, on a white surrounding background having a rapid spatial transition from black to white. A solid color edge may refer to a solid color image, e.g., solid color text, on a white surrounding background having a rapid spatial transition from color to white. A curve of gray values versus spatial pixel positions for each color channel, e.g., red, green and blue color channels, may be generated. A misregistration error may then be calculated by calculating the offset between the color channel curves. The misregistration error may then be used to calibrate the scanner to compensate for the detected color misregistration.

Abstract: Disclosed is a method, system, and program for managing calibration files in a printing system. Patches are printed using a screening algorithm and incorporating at least one output appearance factor. A calibration file is generated from measured color values of the printed patches mapping a color space for the printed patches to a color space of a printer used to print the patches. Information is associated with the calibration file indicating the printer and at least one output appearance attribute for use in selecting one calibration file to use when printing a print job.

Abstract: Provided are a method, system, and program for processing graphics input. The graphics input may include a first and second types of graphics matter, such as line art and continuous tone. At least two data structures including representations of a same graphics matter are provided. An object is generated to include information on the data structures, including information relating the data structures. The object is then processed to produce graphics output including the graphics matter in the graphics input.

Abstract: A duplex printing system including two print engines arranged in tandem for printing a first and second density patch on a print medium, at least one density sensing device adapted for measuring the density of the first and second density patches printed on the print medium by the two print engines and a control for controlling the adjustment of the print engines to enable the density and dot gain of the print output of the first and the second print engines to match. The printing system of the present invention is further characterized by the measurement of the density of the density patch printed by each print engine after the print medium has advanced through the printing system. Thus, the print medium and first and second density patches printed by each print engine is subjected to the same conditions and influences as a print job processed by the printing system.