Hewlett-packard Development Company, L.p.

Hewlett-packard Company

Joan Manuel Garcia

Alejandro Manuel De Pena

Francesc Subirada

Antoni Gil Miquel

Santiago Reyero

Doron Shaked

Izhak Baharav

Elizabeth Zapata

Josep Maria Serra

Francisco Guerrero

Gonzalo Gaston

Andrew Mackenzie

Lidia Calvo

Shailendra Kumar

Juan Carles Vives

Andreu Gonzalez

Javier Lagares

Santiago Garcia Reyero

Antoni Gil Miguel

Santiago Garcia-Reyero

Emiliano Bartolom&eacute;

Santiago Garcia Reyerp

One aspect of the method/apparatus finds, for each input-image pixel, an 'offset weighted average' of neighboring-pixel interactions&#x2014;and uses the averages to make a final image. Another aspect assumes a value for each pixel, to use in a final rendered image form&#x2014;and, at each in a series of approximations, determines whether to change the value, and finds a probabilistic weight to help determine. Yet another finds, for each pixel, a numerical representation of neighboring-pixel interactions&#x2014;and establishes a distance cutoff for use in defining 'neighbor', and uses the representation to decide whether to change color values. Still another finds a desired or ideal number of print passes, and adapts the number of passes actually used to the found number. Another combines halftoning and printmasking into one procedure and prints images prepared thereby. Another integrates halftoning and image filtering, to obtain esthetic visual effects, into one procedure&#x2014;and prints images thus prepared.

Ising-model image rendition, and consolidated masking and/or filtering, in incremental printing

A method for preparing a mask for multi-pass printing, comprises determining a characteristic satellite drop spray pattern for printing in a multi-pass mode with a printhead. Positions in the mask are filled with pass numbers. The pass numbers in a given position are selected based on considerations of interactions among main drops and satellite drops.

Method for preparing a print mask

A diagnostic technique allows an easy visual detection of poor media advance calibration. The diagnostic technique employs a print mode that prints different areas of the plot at different passes with a controlled amount of advances between them. The dot positioning error in the different areas has a non-systematic nozzle contribution, that tends to cancel out, and a systematic contribution due to the accumulative media advance error. Different patterns can be used to make the dot positioning error due to the accumulative media advance error show up. By increasing the number of media advances between the printing of sets of pixels, e.g. pixels in a horizontal line, the effect of accumulated errors and the apparent visual effect is increased.

Diagnostic for visual detection of media advance errors

A technique for assessing nozzle health of a printhead nozzle array in a printing system includes printing a swath portion of an image, optically scanning the printed swath portion to capture a scanned image, comparing an expected image of the swath portion of the image with the scanned image, and assessing whether any nozzles of the nozzle array have malfunctioned. A sensor can be mounted on a printhead carriage to accomplish the image capture.

Method and apparatus for assessing nozzle health

A printer is made by one firm; a RIP made/programmed by a separate RIP firm processes and sends to the printer image data; a two-bit data pipeline passes data through the RIP; a drop table converts data in the pipe to printer resolution. RIP firms set up the table with output dot-per-pixel structure different from the pipe. Ideally the table is in the printer but formed by the RIP; the RIP has precooked printmask instructions, and the printer, popup instructions to refine mask instructions; the instructions hide nozzle-out error and fix which pass prints each pixel; a computer, monitor etc. receive/create data and pass them to the RIP. Another aspect: a printer has a plural-bit data pipe, and interface to accept an external table to convert data from the pipe to numbers of dots per pixel. The interface best accepts a printmode recipe too.

Externally customized tonal-hierarchy configuration and complementary business arrangements, for inkjet printing

A program creates a unitary mask for use over a whole image, with one pattern. The mask need not be full image size; it may be tiled. In the field a printer forms a mask and prints with it, best in the same session, before another image needing another mask, whether due to different image activity or type, or operating conditions. Constraints are controlled to ensure solution. Printout can start before a mask (even the part needed to finish a top swath) is done, going columnwise in each swath. In other invention facets, a program forms a mask of size significant relative to the program and prints with it. Other facets check print conditions and form adapted masks; or find nozzles that cannot back up a known-failed nozzle and to back it up form masks with all able nozzles; or assess image activity and inject mask randomness accordingly.

Masks on demand for use in incremental printing

One invention aspect forms a mask and matrix of corresponding backups for values in the mask, checks when a mask value is not working, and replaces only that value with only a matching matrix entry. A second matrix of further backups is best formed. Another aspect forms a mask as a matrix of stacks of matching entries for mask positions; selects an entry for each position from the matching matrix stack; and prints using the selected entry at each position. Another aspect forms a mask as a matrix of stacks of matching entries for mask positions, and rotates each stack to select an entry for each position. Another aspect forms a mask and a matrix of stacks of backups; finds nonworking mask values and replaces such values with backups from a matching stack. Another aspect forms a seminal mask, tiles it to make a larger one with related properties, and injects noise to disrupt tiling-caused regularity and form a less-regular mask.

Automated and semiautomated printmask generation for incremental printing

Banding reduction in incremental printing, through use of complementary weights for complementary printhead regions

Growing community of inventors

Barcelona, Spain

Joan Manuel Garcia