Abstract:
A method for transforming input color values of a digital image to produce suitable output color values for use by a particular device is disclosed. In this method a plurality of color transforms are stored, each such transform responds to input color values of a digital image and produces output color values which can be used by the particular device. In the method an intermediate transform which is user desirable for transforming the input color values is formed by interpolating between the plurality of transforms.
Abstract:
This invention provides a method for mapping an input color space to an output color space in such a way that the color reproduction characteristics of the saturated colors can be adjusted in a custom manner, while maintaining the desired tone reproduction on the neutral axis. This is accomplished by defining independently a tone transformation and a transformation for a plurality of highly saturated colors. A transformation is formed for the remaining color values having the specified transforms for the neutral and saturated colors as boundary values. In the preferred embodiment multi-dimensional look-up tables are used to implement the transform.
Abstract:
This invention minimizes the color errors associated with performing conversion and/or correction of color digital image data using multi-dimensional look-up tables of a limited size. By distributing the errors across the color gamut it is possible to reduce the average color error as well as the maximum color errors associated with linear or conventional linear or nonlinear, e.g. cube-root or logarithmic, remapping schemes. The resulting advantage will be color images with greatly reduced artifacts.
Abstract:
A method for multi-toning an input digital image having input pixels with two or more color channels to form an output digital image having modified output levels. The method includes determining modified output levels using a combined error signal formed from intermediate error signals for each color channel together with an error signal offset value, and adjusting the input levels for the nearby pixels responsive to weighted error signals.
Abstract:
A method for determining a sharpness predictor for an input digital image includes determining one or more image metrics by analyzing the input digital image; and determining the sharpness predictor from the one or more image metrics.
Abstract:
A method for printing an input digital image using a digital printer having a set of colorants with substantially the same color but different densities, including a sequence of node points where each of the two or more colorants are either at their maximum or minimum values, setting colorant concentrations such that the color channel output responses corresponding to the sequence of node points are substantially equally spaced in a visually uniform color space; forming colorant control look-up tables to provide smooth transitions in the color channel output response between the sequence of node points; addressing the colorant control look-up tables with the printer code value for each pixel of the input digital image to determine the colorant control signals for each of the two or more colorants; and controlling the digital printer using the colorant control signals to produce a print of the input digital image.
Abstract:
A method for determining colorant control values for a color imaging device having four or more colorants is disclosed. The method includes defining a color mapping for a set of paths through a three-channel color space, defining a color mapping function for the three-channel color space relating the three-channel color space values to colorant control values for the four or more colorants of the color imaging device by interpolating between the color mapping defined for the set of paths, forming a forward three-channel color model relating the three-channel color space values to device-independent color values, inverting the forward three-channel color model to determine an inverse three-channel color model relating the device-independent color values to the three-channel color space values, and combining the inverse three-channel color model and the color mapping function to determine an inverse device color model.
Abstract:
A method for automatically compensating for scanner metamerism errors associated with scanning input images using a digital color image scanner, wherein the input images can be on a variety of different input media having colorants with different spectral characteristics, comprising scanning an input image on a digital color image scanner to produce a scanned image; determining one or more estimated color balance error values in a color balance parameter space by analyzing the scanned image using a color balance analysis algorithm; assigning an input medium from a set of possible input media for the scanned input image in response to the estimated color balance error values; selecting a scanner metamerism correction color transform associated with the assigned input medium; and applying the selected scanner metamerism correction color transform to the scanned image to produce a corrected image compensated for scanner metamerism errors.
Abstract:
A method for providing a user access to an extended color gamut digital image and for obtaining payment therefor, comprising the steps of representing the extended color gamut digital image with a limited color gamut digital image and one or more associated residual image(s) representing a difference between the extended color gamut digital image and the limited color gamut digital image; storing the limited color gamut digital image and the associated residual images(s) in an electronic memory; providing the user or user's designee access to the limited color gamut digital image in the electronic memory to provide a preview image; obtaining a payment identifier from the user and making payment using such payment identifier to permit the user or user's designee access to the associated residual image(s); and providing the user or user's designee access to the associated residual image(s) in the electronic memory.
Abstract:
A method for correcting for exposure in a digital image, including the steps of providing a rendered digital image suitable for display and displaying such digital image; using an adjustable exposure setting to nonlinearly modify the rendered digital image to effect an exposure change and displaying the exposure modified rendered digital image; and iteratively changing the adjustable exposure setting in accordance with the nonlinear function to continuously change the exposure setting and display modified digital images until a desired exposure modified rendered digital image is displayed.