An image processing method converts an original image represented in an original color gamut to a target image represented in a target color gamut. The image processing method comprises: A) calculating a set of primary color direction deviations between a set of original primary color directions of the original color gamut and a set of target primary color directions of the target color gamut, wherein each of the set of primary color direction deviations corresponds to a primary color; B) determining, for each pixel in the original image, a corrected color coordinate of the pixel based on a set of offsets of an original color coordinate of the pixel in the original color gamut relative to the set of original primary color directions and the set of primary color direction deviations; and C) mapping, for each pixel in the original image, the corrected color coordinate of the pixel into the target color gamut to generate a target color coordinate of the pixel in the target color gamut.

An image processing apparatus includes a processor configured to adjust a reproduction parameter for correcting image visibility by changing a degree by which the reproduction parameter is to be changed from a reference value in accordance with a ratio of a second color gamut to a first color gamut. The first color gamut indicates a range in which an image is expressible by a first device. The second color gamut indicates a range in which an image is expressible by a second device.

The present principles relate to a method and device for gamut mapping from a first color gamut towards a second color gamut. The method comprises obtaining a preserved key color (prsv_color.sub.K0) and a hue alignment angle (⊖.sub.K0) of the key color (color.sub.K0) for each key color (color.sub.K0) of at least 3 key colors to define a preserved gamut and a rotated gamut; and performing a hue mapping of a current color (color) from the first color gamut towards the second color gamut wherein in case the current color (color) is in a preserved gamut defined by the preserved key color (prsv_color.sub.K0), the hue mapped current color is unchanged, and in case the current color is out of the preserved gamut, the hue mapped current color is calculated from the hue alignment angle (⊖.sub.K0) of two adjacent key colors of the current color (rotated gamut) and from the preserved area.

Techniques for interactively determining/visualizing the color content of a source image and how the corresponding image data is mapped to device colors are described herein. For example, the color content of a digital image can be converted between different color spaces to identify gamut limitations of an output device (e.g., a printing assembly), discover color(s) that cannot be accurately reproduced, etc. Color space conversions enable the transformation of the color content of the digital image from device-specific colorants to a device-independent representation (and vice versa). In some embodiments, these transformations are facilitated using lookup tables that are implemented in graphical processing unit-resident memory.

A display device capable of displaying images with wide color gamut is provided. A display device capable of displaying images with wide color gamut and capable of relaxing contrast made by narrow spectra is provided. The display device includes a liquid crystal element and a light-emitting element. Light obtained from the liquid crystal element through a color filter has an NTSC area ratio of more than or equal to 20 percent and less than or equal to 60 percent and light emitted by the light-emitting element has a BT.2020 area ratio of more than or equal to 80 percent and less than or equal to 100 percent.

A method for adjusting color saturation can determine a saturation adjustment from metadata that specifies an adjustment of color saturation based on a first display and from precomputed data, such as data in one or more look-up tables, that specifies a relationship between image data in a first color space and image data in a second color space. An input image in the first color space is converted into an image in the second color space, and the color saturation is adjusted while the image data is in the second color space, which can be a geometrically non-symmetrical color space.

Example color resources are generated. A first luminosity amount of a greyscale color in a greyscale color space is determined. The greyscale color corresponds with a transformation of a source color in a first color space converted to the greyscale color. The source color corresponding with a depletion color in a second color space, and the depletion color has a second luminosity amount. A target color in a color resource is generated via adjusting a black channel amount in the depletion color to match the second luminosity amount with the first luminosity amount. The target color to correspond with the source color in the color resource.

An example color resource is generated. A source color from a first color space is converted to a corresponding greyscale color in a greyscale color space. The greyscale color includes a first luminosity amount. A black channel amount is adjusted to a depletion color from a second color space to form a target color in the second color space. The depletion color corresponds with a transformation of the source color into the second color space. The depletion color includes a second luminosity amount, and adjusting the black channel includes matching the second luminosity amount in the target color with the first luminosity amount.

A method for adjusting color saturation can determine a saturation adjustment from metadata that specifies an adjustment of color saturation based on a first display and from precomputed data, such as data in one or more look-up tables, that specifies a relationship between image data in a first color space and image data in a second color space. An input image in the first color space is converted into an image in the second color space, and the color saturation is adjusted while the image data is in the second color space, which can be a geometrically non-symmetrical color space.

Video processing techniques and pipelines that support capture, distribution, and display of high dynamic range (HDR) image data to both HDR-enabled display devices and display devices that do not support HDR imaging. A sensor pipeline may generate standard dynamic range (SDR) data from HDR data captured by a sensor using tone mapping, for example local tone mapping. Information used to generate the SDR data may be provided to a display pipeline as metadata with the generated SDR data. If a target display does not support HDR imaging, the SDR data may be directly rendered by the display pipeline. If the target display does support HDR imaging, then an inverse mapping technique may be applied to the SDR data according to the metadata to render HDR data for display. Information used in performing color gamut mapping may also be provided in the metadata and used to recover clipped colors for display.