Apple Inc.

Michael D Stokes

Kok S Chen

Jesse Michael Devine

Alan D Beck

Thomas E Mohr

Iue-Na Steve Swen

Andrew B Morgan

The present invention is directed to producing and reproducing an image using a tone reproduction curve which has been selected based on statistical evaluation of psychophysical data, such as psychophysically quantified subjective judgements. By providing a controlled acquisition and evaluation of psychophysical data to select a tone reproduction curve, visually improved imagery can be assured. Further, once a procedure for controlled acquisition and statistical evaluation of psychophysical data has been established for a given environment, lesser skilled technicians can be used to carry out selection of a tone reproduction curve.

Generation of tone reproduction curves using psychophysical data

Methods and systems for automatically generating printer profiles for color printers to evenly distribute translation errors between device color spaces are described. Since the color spaces of source devices, e.g., monitors and scanners, differs from that of destination devices, e.g., printers, translation is necessary. As some colors may be available to source devices which are not available to destination devices, this translation is inherently imperfect. Moreover, conventional techniques apply imperfect models of the color space which further skew the results. According to the novel methods and systems described herein, a nonlinear regression technique is applied in an automated system which reduces perceptual changes.

Method and system for automatically generating printer profiles

A computer is provided with sets of switchable resources and utilities that enable the user to select from among a number of color paradigms within which to work. These resources include different operating system support services, such as different color pickers that are respectively directed to the different paradigms. The utilities include some whose operations are integrated with application programs, and others which function on a stand-alone basis. A color personality agent requests the computer user to select a particular color paradigm with which to work. In response to the user's selection, the agent selects the appropriate resources and utilities for that paradigm, to provide full color management that is consistent with the user's designated preferences. All subsequent color-related operations are carried out in accordance with the selected paradigm, in a manner that is transparent to the user and application programs running on the computer.

System for providing switchable color paradigms in computers

A method and system for embedding a device profile into a document and extracting a device profile from a document in a color management system. A tagged-element device profile allows for selective access to the device profile. The method of embedding a device profile into a document include allocating memory for a buffer, sending a ready call, transferring the device profile or portions of the device profile into the buffer and writing the same in the document, and lastly, sending a completed call. The method of extracting a device profile from a document includes allocating memory for a buffer, sending a ready call, reading the device profile or portions of the device profile from the document into the buffer and transferring the same to a file, and finally, sending a completed call.

Method and system for embedding a device profile into a document and

A method and system for compressing and color transforming image data are presented. Color transformation is a process whereby perceptional differences between the expressions of images in color devices are compensated. By transforming a compressed version of the image data, the amount of time in which it takes to perform color transformation can be reduced. Selection of compression techniques which maintain color characteristics of the image data in its compressed form permits the usage of color transformation techniques which already exist for the image data in its uncompressed form. The inventive techniques can be applied either prior to, or after, storage of the image data in an intermediate media or transmission from one device to another.

Method and system for color image compression in conjunction with color

An image processing system provides a single interface between the application program and the operating system, through which all image processing services are accessed. This interface includes a dispatcher which directs a call for a particular image processing function, as well as calls that require color matching, to the appropriate components which perform the desired services. Various functions such as color modeling, image compression, image format translation, and standard image processing are available to all application programs through the computer's operating system, in addition to color matching. This approach supports such operations as process scripting and hardware acceleration, to thereby enhance the features and efficiency of functions that are available to the user.

Color image processing system which provides multiple image processing

A method and apparatus for editing color LUTs that are utilized for converting color data from a first display device having a corresponding first color space to a second display device having a corresponding second color space is described. The method of the present invention includes initially displaying on an editor display screen, a graphical representation of a first draft of a previously created color LUT. The graphical representation of the previously created table is embodied as a lattice structure, where each element in the lattice structure represents one or more color values stored in the color LUT. Also displayed on the editor display screen is a set reference images and a set of sample images. The reference images represent the appearance that the user wants the color image to look like on the second display device. Initially, sample images reflect the manner in which the reference image would be displayed on the second device when processed through the previously created color LUT. In an editing session, the user has the ability to edit the manner in which the sample image will appear on the second display device by moving elements within the graphical representation thereby causing corresponding changes in the previously created color LUT. After making the changes to the graphical representation, the sample images are again generated by processing the color data for the reference image through the edited color LUT. The editing session continues, i.e. manipulating the graphical representation, until the color table has been edited such that the sample images appear to have the same color as the reference images.

Real-time three-dimensional color look-up table interactive editor

A method and system for automatic characterization of a color printer are described. A relatively few number of test samples are printed and measured to create an analytic model which characterizes a printer. This analytical model, in turn, is used to generate a multidimensional lookup table which can then be used at runtime to compensate image input and create desired visual characteristics in the printed image. A detector can be incorporated into the printer which measures at least one parameter of each printed sample so that characterization can be carried out internally to the printer in a manner which is transparent to the end user. In this way, changes in paper stock, inks, or environment can be custom compensated for each printing application.

Method and system for analytic generation of multi-dimensional color

A method is provided for use in a color computer graphics system whereby mapping constraints are relaxed and redefined so as to allow out-of-gamut colors to be mapped to in-gamut colors in a manner that is significantly more visually pleasing than in conventional methods. More particularly, the present invention provides a method of mapping source device colors to destination device colors in a computer graphics system having a color image source device and a color image destination device having non-coincident color gamuts such that a plurality of colors within a color gamut of the source device are out of gamut colors outside a color gamut of the destination device. A color name is associated with an out-of-gamut color, which is mapped to a first in-gamut color within the color gamut of the destination device. A color name is also assiciated with the first in-gamut color. If the color name associated with the out-of-gamut color and the color name associated with the first in-gamut color are different, the out-of-gamut color is remapped to a different in-gamut color within the color gamut of the destination device. The color name associated with the out-of-gamut color and the color name associated with the first in-gamut color are based on psychophysical experimentation, i.e., are indicative of what an average user is likely to call the color in question. The remapping may be single-step or iterative.

Subjectively pleasing color gamut mapping in a color computer graphics

A method and system for formatting characteristic CRT information into a standardized format to provide a dynamic CRT characteristic profile to enhance presently used methods of recalibrating CRTs is disclosed. Present CRT parameters are measured and combined with previously acquired calibration parameters in order to create updated characteristic information for the profile. The characteristic information includes the CRT color gamut, the white and black point of the CRT and the gamma of the CRT. In addition, ambient lighting conditions may be included in the profile. This characteristic information is stored in a CRT characterization profile in a standardized format. The profile is updated whenever the CRT is recalibrated or whenever the operating conditions of the CRT are changed. Further, the profile may be employed to recalibrate a destination CRT based on a source CRT's profile.

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Cupertino, CA, United States of America

Michael D Stokes