Abstract: A file of digital color data representing a color image is transformed into a new file of digital color data where one or more colors have been transformed to one or more new color locations where their reproduction is known to be preferred. The digital color data is provided in a multi-dimensional color space where the color locations to be operated on in the color space are designated as color magnets. The color space distance is then calculated between the color locations of the digital color data in the color space and the color magnets. A particular activity is prescribed for each color magnet that affects nearby color locations in the color space; this activity includes one or more activity selected from the group including attraction, repulsion, shielding and dragging.

Abstract: A method for generating a transform for converting a digital color image signal expressed as color values in a first color space having a first color gamut to code values for driving an output device having a second color gamut different from the first color gamut includes the steps of: transforming the color values of the first color space to color values in an intermediate color space; specifying one or more predefined color regions in an intermediate color space; preferentially mapping the color values in the intermediate color space into the second color gamut by smoothly translating the color values to fit the second color gamut while restricting the mapping to regions outside of the predefined color regions to produce enhanced modified color values in the intermediate color space; and transforming the modified color values to code values for driving the output device.

Abstract: A method for producing a numerical representation of perceived overall image quality of a digital test image, including creating a digital reference image series of a reference scene which differ from each other in at least one perceptual attribute, wherein each digital reference image has a corresponding numerical representation of its overall image quality; iteratively displaying one of the digital reference images and comparing that digital reference image with the displayed digital test image and continuing the process until the numerical representation of the digital test image may be satisfactorily inferred; and recording the numerical representation corresponding to the digital test image.

Abstract: An apparatus for producing a numerical representation of perceived overall image quality of a test image includes a viewing support for mounting the test image; a reference image holder disposed relative to the test image on the viewing support, and a source of light for uniformly illuminating the test image and the reference image disposed at the viewing position for viewing by a user. The apparatus can also include a guide with a track.

Abstract: A method for generating a transform for converting a digital color image signal expressed as color values in a first color space having a first color gamut to code values for driving an output device having a second color gamut different from the first color gamut includes the steps of: transforming the color values of the first color space to color values in an intermediate color space; specifying one or more predefined color regions in an intermediate color space; preferentially mapping the color values in the intermediate color space into the second color gamut by smoothly translating the color values to fit the second color gamut while restricting the mapping to regions outside of the predefined color regions to produce enhanced modified color values in the intermediate color space; and transforming the modified color values to code values for driving the output device.

Abstract: A generalized grain ruler incorporating a plurality of uniform patches representing a range of granularities, each patch being a perceptually distinct representation of graininess spaced at perceptually uniform intervals and recorded in an increasing sequence of graininess. A method for producing a generalized grain ruler for the measurement, by comparison of, grain in a reference imaging system generated image, comprising, the steps of:a) generating a set of random numbers for each image component;b) filtering each set of random numbers to alter the Wiener spectrum to result in a filtered set of random numbers that look as if they were generated by the reference photographic system; andc) delivering the filtered set of random numbers to an output device that renders them into an image which is the generalized grain ruler.