Abstract:
A profile generation module which generates colorimetric color profiles based on spectral data and user input on viewing conditions, light source, and medium. In situations where the available color profiles are colorimetric, the colorimetric color profiles are passed to the color management system. In situations where spectral color profiles are available, the profile generation module accesses the spectral profile and the user input. If the user input specifies a medium, the profile generation module also accesses the media module to predict spectral reflectance data for the specified medium. The profile generation module generates the calorimetric color appearance profile based on the user input, and generates the calorimetric color device profile based on the user input and the spectral data. In this way, calorimetric color profiles are generated as needed, and spectral data can be used with calorimetrically based color management systems.
Abstract:
The conversion of colors of an image from a source color space to a destination color space, the source color space being represented by a source color space transformation associated with a source color profile, and the destination color space being represented by a destination color space transformation associated with a destination color profile, is provided. Digital values corresponding to colors contained in the image are converted from the source color space to digital values in a device-independent color space, using the source color space transformation. A gamut mapping is determined from a source color gamut to a destination color gamut, by using a source gamut boundary description constructed from a source image profile which is separate from the source color profile, or by using a destination gamut boundary description constructed from a destination image profile which is separate from the destination color profile. The digital values in the device-independent color space are converted to corresponding digital values in the device-independent color space using the gamut mapping, wherein the converted digital values represent gamut mapped digital values between the source gamut boundary description and the destination gamut boundary description. The gamut mapped digital values in the device-independent color space are transformed to corresponding digital values in the destination color space, using the destination color space transformation.
Abstract:
A method of modeling spectral characteristics of an input imaging device comprising includes adjusting digital values measured from a target to be linear relative to luminance of neutral patches of the target, for each channel of the input imaging device. The method further includes modifying the adjusted digital values to compensate for cross-channel interaction, for each channel of the input imaging device. In addition, the method includes converting the modified digital values to a spectrum, for each channel of the imaging device. An apparatus for modeling spectral characteristics of an input imaging device is also provided.
Abstract:
Conversion of colors of an image from a source color space to a destination color space by use of both a color profile and an image profile. The source and destination color spaces are respectively represented by source and destination color space transformations associated with source and destination color profiles. Colors in an image are converted from the source color space to a device-independent color space, using the source color space transformation. A gamut mapping is determined from a source color gamut to a destination color gamut, by using a gamut boundary description constructed either from a source image profile which is separate from the source color profile, or from a destination image profile which is separate from the destination color profile. The gamut mapping is applied, and the gamut mapped colors are transformed from the device-independent color space to the destination color space, using the destination color space transformation.
Abstract:
A method of modeling spectral characteristics of an input imaging device comprising includes adjusting digital values measured from a target to be linear relative to luminance of neutral patches of the target, for each channel of the input imaging device. The method further includes modifying the adjusted digital values to compensate for cross-channel interaction, for each channel of the input imaging device. In addition, the method includes converting the modified digital values to a spectrum, for each channel of the imaging device. An apparatus for modeling spectral characteristics of an input imaging device is also provided.
Abstract:
A method of generating a color characterization model for an input imaging device includes capturing a target having plural patches using the input imaging device to produce plural digital values in a device-dependent color space, the plural digital values having corresponding target measurements in a color characterization set. The method further includes determining if any of the plural digital values are collinear with each other, and removing, in a case where it is determined that digital values are collinear with each other, at least one of the collinear digital values and corresponding target measurements from the color characterization data set. In addition, the method includes generating the color characterization model for the input imaging device based on the plural digital values and corresponding target measurements remaining in the color characterization set. An apparatus for generating a color characterization model for an input imaging device is also provided.
Abstract:
A profile generation module which generates colorimetric color profiles based on spectral data and user input on viewing conditions, light source, and medium. In situations where the available color profiles are colorimetric, the colorimetric color profiles are passed to the color management system. In situations where spectral color profiles are available, the profile generation module accesses the spectral profile and the user input. If the user input specifies a medium, the profile generation module also accesses the media module to predict spectral reflectance data for the specified medium. The profile generation module generates the calorimetric color appearance profile based on the user input, and generates the calorimetric color device profile based on the user input and the spectral data. In this way, calorimetric color profiles are generated as needed, and spectral data can be used with calorimetrically based color management systems.
Abstract:
In general, the invention relates to techniques for reconstructing color channels in a multi-channel display device. The invention may be particularly useful in reconstructing the light source spectra for the color channels of liquid crystal displays (LCD). In order to accurately model and calibrate a display device, an accurate light source spectrum estimate for each of the individual color channels is needed. In accordance with the invention, a light source spectrum can be determined for each color channel of a display based on measured emission spectra for the color channels, an inverted contrast ratio for the display, and an assumed transmission spectrum for a light valve in the display. The invention provides techniques to compensate for light leakage from adjacent color channels with regards to wavelength dependent transmissions that cause hue shifts in images reconstructed by the display device.
Abstract:
The invention relates to techniques for light leakage compensation in a multi-channel display device. The invention may be particularly useful in calculating single-channel emission spectra for liquid crystal displays (LCD). In order to accurately model and calibrate a display device, an accurate spectral output estimate for each of the individual color channels is needed. The invention provides techniques to compensate for light leakage from adjacent color channels that cause hue shifts in the images reconstructed by the display device. In accordance with the invention, a light leakage emission spectrum can be determined for each color channel of a display based on a measured emission spectrum for the display at a minimum level and assumed emission spectra for light sources in the display. A single-channel emission spectrum is the difference between a cumulative color channel emission spectrum measurement and the light leakage spectra of adjacent color channels.