Abstract: One embodiment of a method for finding an aim position of a measuring device may include building a color model for an imaging device, initializing a color encoding image, displaying or printing the image on the imaging device, acquiring measurement with the measuring device, converting the measurement into imaging device code values using the color model, calculating said aim position from said device code values. The color encoding image sets one-to-one relationship between coordinates and colors. The image is output on the imaging device and measured by the measuring device. The measurement is converted using the color model to the device code values. The aim position then calculated from position of the device code values in the encoding image.

Abstract: Techniques are provided to encode and decode image data comprising a tone mapped (TM) image with HDR reconstruction data in the form of luminance ratios and color residual values. In an example embodiment, luminance ratio values and residual values in color channels of a color space are generated on an individual pixel basis based on a high dynamic range (HDR) image and a derivative tone-mapped (TM) image that comprises one or more color alterations that would not be recoverable from the TM image with a luminance ratio image. The TM image with HDR reconstruction data derived from the luminance ratio values and the color-channel residual values may be outputted in an image file to a downstream device, for example, for decoding, rendering, and/or storing. The image file may be decoded to generate a restored HDR image free of the color alterations.

Abstract: Techniques are provided to encode and decode image data comprising a tone mapped (TM) image with HDR reconstruction data in the form of luminance ratios and color residual values. In an example embodiment, luminance ratio values and residual values in color channels of a color space are generated on an individual pixel basis based on a high dynamic range (HDR) image and a derivative tone-mapped (TM) image that comprises one or more color alterations that would not be recoverable from the TM image with a luminance ratio image. The TM image with HDR reconstruction data derived from the luminance ratio values and the color-channel residual values may be outputted in an image file to a downstream device, for example, for decoding, rendering, and/or storing. The image file may be decoded to generate a restored HDR image free of the color alterations.

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 decoder receives for decoding and post-processing for display an HDR (high dynamic range) image comprising a first coded image (e.g., a JPEG-HDR baseline image) and a second coded image (e.g., a JPEG-HDR ratio image). The first coded image is partially decoded and post-processed according to a post-processing command (e.g., scaling) to output a first decoded and post-processed image. The second coded image is also partially decoded and post-processed according to the post-processing command to output a second decoded and post-processed image. The first and the second decoded and post-processed images are combined to output a decoded HDR image according to the post-processing command.

Abstract: Techniques are provided to encode and decode image data comprising a tone mapped (TM) image with HDR reconstruction data in the form of luminance ratios and color residual values. In an example embodiment, luminance ratio values and residual values in color channels of a color space are generated on an individual pixel basis based on a high dynamic range (HDR) image and a derivative tone-mapped (TM) image that comprises one or more color alterations that would not be recoverable from the TM image with a luminance ratio image. The TM image with HDR reconstruction data derived from the luminance ratio values and the color-channel residual values may be outputted in an image file to a downstream device, for example, for decoding, rendering, and/or storing. The image file may be decoded to generate a restored HDR image free of the color alterations.

Abstract: Techniques are provided to encode and decode image data comprising a tone mapped (TM) image with HDR reconstruction data in the form of luminance ratios and color residual values. In an example embodiment, luminance ratio values and residual values in color channels of a color space are generated on an individual pixel basis based on a high dynamic range (HDR) image and a derivative tone-mapped (TM) image that comprises one or more color alterations that would not be recoverable from the TM image with a luminance ratio image. The TM image with HDR reconstruction data derived from the luminance ratio values and the color-channel residual values may be outputted in an image file to a downstream device, for example, for decoding, rendering, and/or storing. The image file may be decoded to generate a restored HDR image free of the color alterations.

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: Techniques are provided to encode and decode image data comprising a tone mapped (TM) image with HDR reconstruction data in the form of luminance ratios and color residual values. In an example embodiment, luminance ratio values and residual values in color channels of a color space are generated on an individual pixel basis based on a high dynamic range (HDR) image and a derivative tone-mapped (TM) image that comprises one or more color alterations that would not be recoverable from the TM image with a luminance ratio image. The TM image with HDR reconstruction data derived from the luminance ratio values and the color-channel residual values may be outputted in an image file to a downstream device, for example, for decoding, rendering, and/or storing. The image file may be decoded to generate a restored HDR image free of the color alterations.

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: 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: 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.

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 is directed to generic spectral modeling techniques applicable to a variety of imaging devices. A generic spectral model may include a general channel model capable of modeling spectral characteristics of imaging devices and a look-up table (LUT) capable of compensating for cross-channel interaction and possibly other characteristics that are difficult to model, such as non-linear characteristics of imaging devices. In this way, the generic spectral model includes aspects of both a conventional physical model and a conventional brute force model. Digital values, i.e., pixel counts, of each channel of an imaging device are adjusted by the LUT of the generic spectral model to include cross-channel interaction. The channel model then accurately predicts spectral emissions for each channel of the imaging device based on the adjusted digital values. The generic spectral model converts the predicted spectral emissions to a device-independent color space.

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.

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.