Ricoh Production Print Solutions LLC

Ricoh Company, Ltd.

Hewlett-Packard Development Company, L.p.

Rochester Institute of Technology

Sreenath Rao Vantaram

Mikel J Stanich

Larry Mason Ernst

Kartheek Chandu

Chai Wah Wu

Nenad Rijavec

Mark Edward Shaw

Sohail A Dianat

Ranjit Bhaskar

Eli S Saber

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.

Halftone calibration mechanism employing an ink model

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.

Defective nozzle detection 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.

Print head alignment mechanism

The systems and methods presented herein provide for calibrating a print engine of a printing system. The printing system prints image data on a print medium and scans the printed image data. Color values of the scanned image data are then measured and various tints of color values and their transition locations are identified. A calibration module estimates the original optical densities of the identified color value tints and generates a target optical density for each of the identified color value tints using the estimated original optical densities to determine print irregularities in the color values of the scanned image data. The calibration module then generates a halftone screen based on the mean optical densities and applies the generated halftone screen to the print engine to calibrate the print engine.

Printer calibration for printers with fixed print array structures

A multi-resolution color image segmentation algorithm which takes advantage of gradient information in an adaptive and progressive framework is described. A gradient-based segmentation method is initiated with a dyadic wavelet decomposition scheme of an arbitrary input image, accompanied by a vector gradient calculation of its color converted counterpart. The resultant gradient map is used to automatically and adaptively generate thresholds for segregating regions of varying gradient densities, at different resolution levels of the input image pyramid. In combination with a confidence map and non-linear spatial filtering techniques, regions of high confidence are passed from one resolution level to another until the final segmentation at highest (original) resolution is achieved.

Methods for adaptive and progressive gradient-based multi-resolution color image segmentation and systems thereof

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.

Growing community of inventors

Rochester, NY, United States of America

Sreenath Rao Vantaram