Abstract: A parallel Raster Image Processor system that includes a plurality of Raster Image Processors (RIPs) for parallel processing of a print job into a printer-ready format for the printing of the print job and a splitter for splitting the print job into a plurality of chunks and sending the chunks of the job to the plurality of the RIPs for processing. The print job includes objects described in a page description language. The splitter is configured to: interpret the job to determine the objects required by each of the plurality of the RIPs to process corresponding received chunks; store the determined objects to maintain knowledge of the determined objects; and send the determined objects along with the corresponding chunks to the designated RIPs to process the corresponding chunks, if the same determined objects are not already with the designated RIPs.

Abstract: A parallel Raster Image Processor system that includes a plurality of Raster Image Processors (RIPs) for parallel processing of a plurality of document jobs into a printer-ready format for the printing of the document jobs and a splitter. The splitter configured to combine the plurality of document jobs to form a plurality of chunks, each chunk is sent to a respective designated RIP for processing.

Abstract: A receiving subsystem receives a print job to be raster image processed. A job splitter divides the print job into print job chunks and distributes the print job chunks to at least two raster image processors. The raster image processors perform raster image processing on corresponding ones of the print job chunks. A cache supervisor coordinates creation use and destruction of said reusable raster image objects by said raster image processors.

Abstract: Disclosed are methods and apparatus for operating a page parallel RIP printing system including a plurality of image marking engines (IMEs). According to an exemplary method, a print job is split into a plurality of job chunks, each job chunk grouped by its destination IME; and the job chunks are processed into a printer ready format by a plurality of RIP nodes associated with the job chunk group's respective destination IME.

Abstract: Systems and methods are described that facilitate reducing metamerism in a scanner or printer system by evaluating and manipulating unfiltered clear channel information. Using a four channel model to predict CIE XYZ tristimulus values from RGB and clear, a linear model is generated based on a polynomial matrix conversion. For example, one such model has coefficients weighting 1, R, G, B, W, R2, G2, B2, W2, RG, RB, RW, GB, GW, BW, and corresponding third order terms. The XYZ values predicted by the linear model are converted to L*a*b*, and compared with measured L*a*b* values. A statistic involving the difference between measured and computed L*a*b* values is used as a metric in a non-linear optimization to obtain the best values for the matrix elements. Once the matrix is optimized, it is employed for printer calibration, error detection, and the like.

Abstract: In one form, the method comprises obtaining scanned values of the image, scaling the scanned values to obtain scaled values, applying a non-linear correction function to the scaled values to obtain a first approximation of corrected reflectance values, filtering the corrected reflectance values by applying a piecewise Gaussian filter, applying the non-linear correction function to obtain a successive approximation of the corrected reflectance values, determining whether the successive approximation of the corrected reflectance values are sufficiently converged, selectively repeating the filtering and applying if the corrected reflectance values are insufficiently converged and selecting the corrected reflectance values for subsequent processing if the corrected reflectance values are sufficiently converged.

Abstract: Systems and methods are described that facilitate distributing a raster image processing task for an input file (e.g., an electronic document) across a plurality of nodes (e.g., computers) in a network. The input file is received at a first node, which becomes the controlling node and splits the pages of the input file into interleaved chunks such that adjacent pages are allocated to different chunks (i.e., no chunk contains adjacent pages in the document). Chunks are then assigned to different nodes for concurrent raster image processing. Once complete, the processed pages are returned to the controller node, which logically orders the pages into their original sequential order, and outputs the logically ordered, raster image processed pages to a printer, where they are printed.

Abstract: A printing system is provided comprising a plurality of resources including idle and non-idle resources having a plurality of image marking engines and a user interface for inputting user determinable priority criteria for a first print job. All of the non-idle resources are assigned to the first print job when the first print job is the only print job; and, a resource fraction of the non-idle resources is assigned to the first print job when there is at least a second print job.

Abstract: For a selected class of functions, which describe most typical banding variations, the average response can be found by sampling at only 2Nth locations, where N is the number of different frequencies of significant banding. This approach makes use of the fact that in most applications the banding frequencies of a given printer system, are known in advance, even if the amplitudes of the banding are not known. Each sample point requires a very small test area or pattern, significantly reducing the overall size of the required test areas.

Abstract: Color separation systems and methods improve color constancy and smoothness of a color lookup table (LUT) for a printer. A plurality of nodes of the LUT may be defined in colorimetric space, and the nodes out of the printer gamut may be mapped to the printer gamut surface. All possible colorant combinations are then determined that produce each node in the LUT in a device independent color space based on an inversion of the spectral based printer model. Next, a specific image quality metric combination based on a color inconstancy index (CII) and a gray component replacement (CGR) strategy is defined. And a colorant combination is determined for each and every node in the LUT based on this metric. A smoothing filter may be used to smooth the lookup table.

Abstract: A parallel Raster Image Processor system that includes a plurality of Raster Image Processors (RIPs) for parallel processing of a plurality of document jobs into a printer-ready format for the printing of the document jobs and a splitter. The splitter configured to combine the plurality of document jobs to form a plurality of chunks, each chunk is sent to a respective designated RIP for processing.

Abstract: A parallel Raster Image Processor system that includes a plurality of Raster Image Processors (RIPs) for parallel processing of a print job into a printer-ready format for the printing of the print job and a splitter for splitting the print job into a plurality of chunks and sending the chunks of the job to the plurality of the RIPs for processing. The print job includes objects described in a page description language. The splitter is configured to: interpret the job to determine the objects required by each of the plurality of the RIPs to process corresponding received chunks; store the determined objects to maintain knowledge of the determined objects; and send the determined objects along with the corresponding chunks to the designated RIPs to process the corresponding chunks, if the same determined objects are not already with the designated RIPs.

Abstract: A technique to compress multidimensional color look-up tables by computing an inexpensive fit to the contents of the tables is provided. At each node of the table, the difference between the result of evaluating the fit and the original value at that node are completed. In one form, the parameters of the fit and the differences are stored and compressed, possibly losslessly.

Abstract: What is disclosed is a novel fault tolerant page parallel RIP system having a plurality of distributed RIP nodes and a method for robust recovery in the event of a fault having occurred on the system. In one embodiment, the present fault tolerant page parallel RIP system comprises at least a plurality of RIP nodes, a supervisor node, and a splitter node. The splitter receives a location of the job file and splits the job file into at least one original chunk. In formation sufficient to regenerate the original chunk in the event of a fault condition having occurred on the page parallel RIP system is stored. The splitter then sends the original chunk to a destination RIP node wherein the original chunk is RIP'ed into at least one page in print-ready form. The one page is the provided in print-ready form to an output subsystem. Various embodiments are disclosed.

Abstract: A system using a spatial correction to improve the result of a printer calibration and correction is described. More particularly, in one form, a spatial correction may be used to pre-condition a printer for an improved color calibration. In another form, spatial correction and color calibration are addressed in the same process for color correction.

Abstract: What is disclosed is a novel system and method for generating a color lookup table (LUT) that minimizes interpolation errors over the entire color space, including the off-grid colors. The present method for LUT optimization considers off-grid point errors in assigning entries to the LUT. As described herein further, grid point values are computed that provide a least mean square error solution for the entire printer gamut volume. The present method dramatically reduces errors near the gamut boundary and can be used for populating nodes of any LUT that will be linearly interpolated, not only a table mapping from L*a*b* to CMYK.

Abstract: According to an aspect of the disclosure, a printing system is provided comprising a plurality of resources including idle and non-idle resources having a at least one image marking engine. The plurality of resources includes a page parallel RIP system wherein the RIP system supports configurable sized print chunks. The RIP system adaptively adjusts the size of the chunks according to the busyness of receiving RIP nodes.

Abstract: A method and systems for calibrating a document scanner are provided. The scanner calibration method includes providing a geometrically operative black absorption device having a structural geometry that is capable of receiving light and limiting propagation of the received light, where the black calibration target has a total light reflectance of less than one percent. The method further includes powering on a light source of a document scanner to provide light toward the black absorption device, where the light source generates a noise signal when providing the light. The method further includes detecting, by a sensor of the document scanner, light reflected from the black absorption device and generating calibration signals based on the reflected light and the noise signal.

Abstract: Color separation systems and methods improve color constancy and smoothness of a color lookup table (LUT) for a printer. A plurality of nodes of the LUT may be defined in colorimetric space, and the nodes out of the printer gamut may be mapped to the printer gamut surface. A set of possible colorant combinations are then determined that produce each node in the LUT in a device independent color space using a non-linear minimization algorithm, such as, for example, a conjugate gradient algorithm. Next, a colorant combination may be determined for each and every node in the LUT based on an image quality metric. In some implementations, a smoothing filter may be used to smooth the lookup table.

Abstract: A printing system comprised of a printer, a plurality of processing nodes, each processing node being disposed for processing a portion of a print job into a printer dependent format, and a processing manager for spooling the print job into selectively sized chunks and assigning the chunks to selected ones of the nodes for parallel processing of the chunks by the processing nodes into the printer dependent format. The chunks are selectively sized from at least one page to an entire size of the print job in accordance with predetermined splitting factors for enhancing printer printing efficiency.