Hp Indigo B.v.

Hewlett-packard Development Company, L.p.

Hewlett-packard Indigo B.v.

Yohanan Sivan

Ran Waidman

Gregory Braverman

Carl Staelin

Renato Keshet

Pavel Kisilev

Michal Aharon

Doron Schlumm

Sasi Moalem

Eyal Shelef

Shlomo Harush

Lior Shapira

Boris Oicherman

Lior Katz

Ziv Berkovich

Nir Mosenson

An example method of determining dot gain in a liquid electrophotographic printer is described. The method involves effecting a print operation based on a predetermined digital dot area and measuring an operating current of a binary ink development unit during the print operation. A dot gain between the digital dot area and a physical dot area of a developed image is determined based on a function of the measured operating current.

Liquid electrophotographic dot gain determination

A method for selecting a colorant amount for printing is described in which a maximum optical density of an image is identified. The maximum optical density is compared to with a threshold optical density, and when the threshold is exceeded, dot cluster sizes from a first lookup table are selected, otherwise, dot cluster sizes from a second lookup table are selected. A colorant thickness corresponding to the selected dot cluster sizes is selected for printing the image.

Selecting colorant amount for printing

A method includes forming a second set of printing dots on a photosensitive member by a printing dot applicator corresponding to image data of second portions of the image adjacent to first portions of the image. The second set of printing dots are formed on the photosensitive member after the first set of printing dots have been transferred from the photosensitive member. Thus, a merging of adjacent printing dots due to an electrical interaction there between on the photosensitive member is reduced.

Reduce merging of adjacent printing dots on a photosensitive member

A method comprises computing an activity map for an input image. The activity map indicates an amount of variable spatial activity in the input image. The method further comprises producing an output image based on the activity map, and controlling a printhead to cause the output image to be printed. The output image contains a plurality of color pixels and each such color pixel is represented by at least one of cyan (C), magenta (M), yellow (Y), and black (K) in a color space.

Determining new color values of an image based on an activity map

A method of enabling preparing a printing system calibrated with a first halftone screen for printing with a second halftone screen. The calibration is represented by calibration data. Calibration data for the second halftone screen is produced from the existing calibration data of the first halftone screen without resorting to previous calibration data for the second halftone screen, based on correlation data which represent a first-order correlation between the halftone screens.

Halftone printing with different screens

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Raanana, Israel

Yohanan Sivan