US 5,493,321 A · Method and apparatus of characterization for photoelectric color proofing systems

Abstract

An improved method and apparatus for characterizing a full color gamut of a digital photosensitive color proofing system having at least two separately controllable process parameters uses a one page color standard for calibrating the full color gamut. The one page color standard includes a plurality of color density test areas on the page, with each color density test area having a test patch for each colorant printed at a selected color density that is within a range of color densities, and a plurality of tone rendition test areas on the same page. There is one tone rendition area for each of the color density test areas, and each tone rendition test area has a plurality of test tints for each colorant as a primary color and a plurality of test patches for a set of secondary colors composed from combinations of the primary colors. The method for producing the one page color standard includes the steps of adjusting a first process parameter to produce the plurality of color density test areas, adjusting a second process parameter to produce the plurality of tone rendition test areas, and then printing the single color standard or test pattern page. The characterization process of the present invention involves the steps of measuring selected ones of the test patches and test tints to define or characterize the full color gamut, including a primary color gamut, a secondary color gamut and tone renditions, for the range of color densities. An optional step of mapping or matching the full color gamut of the color proofing system to a full color gamut of a target printing system by establishing the required first and second process parameters can be performed to best optimize a two-dimensional color transfer function between the two color gamuts.

Claims29

Dependent claims

A method of characterizing a full color gamut of a digital photosensitive color proofing system having at least two separately controllable process parameters that control color density and tone reproduction of three or more colorants used to produce a color print image from a digital image, the method comprising the steps of:

(a) adjusting a first process parameter to produce a plurality of color density test areas, each color density test area having a test patch for each colorant printed at a selected color density that is within a range of color densities capable of being primed by the digital photosensitive color proofing system;
(b) adjusting a second process parameter to produce a plurality of tone rendition test areas, one for each of the color density test areas, each tone rendition test area having a plurality of test tints for each colorant as a primary color and a plurality of test patches for a set of secondary colors composed from combinations of the primary colors;
(c) printing a single test pattern page, the test pattern page including both the plurality of color density test areas and the plurality of tone rendition test areas;
(d) measuring selected ones of the test patches and test tints to characterize the full color gamut in terms of a primary and secondary color gamut and tone renditions for the range of color densities creating measurements;
and
(e) optimizing the full color gamut using a predetermined model of the relationship of primary colorant to secondary colors.

3 more elements

A one page color standard for characterizing a full color gamut of an off-press digital photosensitive color proofing system, comprising:

a generally planar support member;
a plurality of color density test areas disposed on the support member, each color density test area having a test patch for each colorant printed at a selected color density that is within a range of color densities capable of being printed by the digital photosensitive color proofing system;
and
a plurality of tone rendition test areas disposed on the support member, one for each of the color density test areas, each tone rendition test area having a plurality of test tints for each colorant as a primary color and a plurality of test patches for a set of secondary colors composed from combinations of the primary colors,
such that selected measurements of the test patches and test tints from a single support member characterize the full color gamut in terms of a secondary color gamut and tone renditions for the range of color densities for the digital photosensitive color proofing system.

2 more elements

A method of characterizing a full color gamut of a digital photosensitive color proofing system having at least one controllable process parameter that control color density of three or more primary colorants used to produce a color print image from a digital image, the method comprising the steps of:

(a) adjusting said process parameter to produce a plurality of color density test areas, each color density test area having a test patch for each colorant printed at a selected color density that is within a range of color densities capable of being printed by the digital photosensitive color proofing system and a plurality of test patches for a set of secondary colors composed from combinations of the primary colorants;
(b) printing a single test pattern page, the test pattern page including the plurality of color density test areas;
(c) measuring selected ones of the test patches to characterize the full color gamut in terms of a primary and secondary color gamut and tone renditions for the range of color densities creating measurements;
and
(d) optimizing the full color gamut using a predetermined model of a relationship of primary colorant to secondary colors.

2 more elements

Dependencies are inferred from the claim text.

Method and apparatus of characterization for photoelectric color proofing systems

Life of this patent

Method and apparatus of characterization for photoelectric color proofing systems

Life of this patent

Abstract

Claims29