Patent application number | Description | Published |
20100045722 | CORRECTION OF PRINT ENGINE ARTIFACTS USING AN ITERATIVE HALFTONING SEARCH ALGORITHM - Methods and systems herein provide for reducing artifacts during printing. One printing system is operable to prepare a continuous tone image (CTI) for printing onto a print medium by generating an initial half tone image (HTI) based on the CTI. The printing system includes a printer and a print controller. The print controller filters the initial HTI and the CTI with a perceptual filter and determines an error between the filtered CTI and the filtered HTI. The print controller prints the HTI via the printer to determine printer artifacts and processes a scanned version of the printed HTI to determine an error between the filtered CTI and the scanned and filtered HTI. This processing updates the initial HTI and reduces the error between the filtered CTI and the filtered HTI. | 02-25-2010 |
20110148968 | MULTI-PASS CALIBRATION IN FIXED PRINTHEAD ARRAY PRINTERS - Methods and apparatus herein provide for automated calibration of multiple printheads used in a multi-pass printing system. Aspects hereof print a plurality of gray scale printed patterns each printed pattern corresponding to a gray scale value for each of the multiple printheads. The printed patterns are then measured to determine the intensity (e.g., optical density) of each of the printed patterns. A measurement function is derived from the measured intensity and gray scale levels used to print each pattern. Calibrated transfer functions are then determined from the measurement function and target function where each calibrated transfer function relates, for a corresponding printhead, an input gray scale level of a pixel in an image to be printed to a calibrated gray scale level to use for the corresponding printhead when operating in multi-pass mode. | 06-23-2011 |
20110280589 | AUTOMATIC PAPER MANAGEMENT AND COLOR PROFILE UTILIZATION - Methods and systems herein provide for calibration of a production printing system that accommodates a plurality of different print paper types, including new paper types with no ICC profiles or optical density curves on file. One exemplary method includes printing test patches of primary colors on a first print medium, measuring colors of the test patches printed on the first print medium to determine an optical density of the first print medium, and comparing the optical density of the first print medium to a plurality of optical density curves to identify a comparable optical density curve of a different print medium. The comparable optical density curve is one of a plurality of optical density curves installed on the production printing system. The method further includes automatically selecting the comparable optical density curve to calibrate the production printing system to the different print medium for use in printing to the first print medium. | 11-17-2011 |
20130076813 | Inkjet Nozzle Flushing Mechanism - A method is disclosed. The method includes receiving print job data, rasterizing the print job data to generate image data for each page of the print job data to be printed, calculating a coverage per unit area for two or more color planes of each page of the image data and calculating a flushing mask to flush nozzles of the inkjet print head. | 03-28-2013 |
20130076820 | Dynamic Inkjet Nozzle Flushing Mechanism - A method is disclosed. The method includes analyzing an image of a first flushing pattern applied on a medium during production of a print job to detect presence of one or more defective ink jet nozzles and adjusting to a second flushing pattern during the production of the print job upon detecting the presence of one or more defective print head nozzles. | 03-28-2013 |
20130176578 | Mask Generation Mechanism - A method is disclosed. The method includes generating a seed pattern which ensures one dot per column, computing an auto correlation function and performing pixel error processing. Pixel error processing includes performing multiple operations during each iteration to create visually pleasing halftone mask patterns which follow a one dot per column constraint. | 07-11-2013 |
20130176599 | Halftone Screen Generation Mechanism - A method is disclosed. The method includes generating a Continuous Tone Image (CTI) with all pixel values same as the first gray level and an initial Half Tone Image (HTI) with all pixel values equal to minimum absorptance level, computing a change in pixel error by toggling with all the possible output states and swapping with all neighbor pixels only if the stacking constraint is satisfied, updating the HTI with the maximum error decrease operation and continue to next pixel location till the end criteria is met. Once the end criteria is met, the updated HTI is saved as a final halftone screen for that gray level and copied as the initial HTI for the next gray level along with CTI pixel values updated to the next gray level till the final gray value is reached. | 07-11-2013 |
20130176600 | Halftone Calibration Mechanism Employing an Ink Model - A printing system is disclosed. The printing system includes a halftone calibration system that receives one or more un-calibrated halftones, generates one or more calibrated halftones using an ink model from the one or more un-calibrated halftones, analyzes a printed calibration screen of the one or more calibrated halftones, and performs a halftone calibration. | 07-11-2013 |
20130257969 | Print Head Alignment Mechanism - A printing system is disclosed. The printing system includes a print engine including two or more print heads to generate an alignment chart and an alignment system. The alignment system receives the alignment chart and computes a magnitude of misalignment between the print heads. | 10-03-2013 |
20130265360 | Defective Nozzle Detection Mechanism - A method is disclosed. The method includes receiving image data from one or more image readers and analyzing the image data to locate and classify artifacts on the medium caused by defective print engine nozzles. | 10-10-2013 |
20130265611 | Hybrid Halftone Generation Mechanism - A method is disclosed. The method includes generating a Continuous Tone Image (CTI) with all pixel values same as a first gray level, generating an initial Half Tone Image (HTI) with all pixel values equal to minimum absorptance level and computing a change in pixel error for a first pixel. The change in pixel error is computed by identifying a first pixel indicated in a valid pixel map, toggling the first pixel with all the possible output states and swapping the first pixel with all neighbor pixels only if the stacking constraint is satisfied, updating the HTI with the maximum error decrease operation and continue to next pixel location till the end criteria is met. | 10-10-2013 |
20130265612 | Hybrid Halftone Generation Mechanism - A method is disclosed. The method includes generating a Continuous Tone Image (CTI) with all pixel values same as a first gray level, generating an initial Half Tone Image (HTI) with all pixel values equal to minimum absorptance level and computing a change in pixel error for a first pixel. The change in pixel error is computed by identifying a first pixel indicated in a valid pixel map, toggling the first pixel with all the possible output states and swapping the first pixel with all neighbor pixels only if the stacking constraint is satisfied, updating the HTI with the maximum error decrease operation and continue to next pixel location till the end criteria is met. | 10-10-2013 |
20130286074 | Inkjet Nozzle Flushing Mechanism - A method is disclosed. The method includes receiving print job data, rasterizing the print job data to generate image data for each page of the print job data to be printed, calculating a coverage per unit area for two or more color planes of each page of the image data and calculating a flushing mask to flush nozzles of the inkjet print head. | 10-31-2013 |
20140233069 | Method and System for Halftoning Using Energy Minimization - A method is disclosed. The method includes generating a set of points via energy minimization to implement halftone seed pattern. | 08-21-2014 |
20140240803 | Toner Estimation Mechanism - A method is disclosed. The method includes estimating a quantity of toner to be used to print a job at a printer by calculating a buildup of toner at edges of data on each page of the print job. | 08-28-2014 |
20140253976 | Hybrid Halftone Generation Mechanism - A method is disclosed. The method includes generating a halftone screen using a Direct Multi-bit Search Screen Algorithm (DMSSA) to optimize a halftone pattern at each gray level. | 09-11-2014 |
20150055185 | Halftone Mechanism - A method is disclosed. The method includes applying a human visual system (HVS) model to a Continuous Tone Image (CTI) and a initial Half Tone Image (HTI) to generate a perceived CTI and a perceived HTI and computing a change in pixel error for a first pixel by toggling the first pixel with all the possible output states and swapping the first pixel with all neighbor pixels. | 02-26-2015 |