Method for describing an actual color gamut of a color device or of a color content
View Patent ↗To describe the actual color gamut, a hierarchical structure is proposed which comprises, from bottom to top: Gamut Components: each GC is a surface, generally described as a set of connected elementary triangles or polygons. Gamut Hulls: each GH is a closed surface formed by the concatenation of connex Gamut Components. Gamut Instances: each GI is an alternative Gamut Boundary Description of the same actual gamut and is built by the union of the volume(s) bordered by at least one Gamut Hull. Such a Gamut Boundary Information may be notably used for gamut mapping operations. Among advantages of the invention, are flexibility and adaptation to available memory and bandwidth capabilities.
1. A video sink configured to implement a method for describing, in a color space, an actual color gamut by at least one gamut boundary description, called gamut instance wherein said method comprises:
defining of at least one gamut hull as a closed surface bordering a volume, such that each gamut instance is formed by the union of the volume(s) bordered by at least one gamut hull;
defining a plurality of gamut components such that each gamut hull is formed by the concatenation of several connex gamut components, wherein each gamut component represents a surface that is meshed into a plurality of connex faces, wherein at least one gamut component of said plurality of gamut components is used for the definition of at least two different gamut hulls.
2. The video sink according to claim 1 , wherein the method further comprises defining a plurality of gamut hulls, wherein the volumes of at least two of said gamut hulls of said plurality that are used to define a same gamut instance have a non-empty intersection.
3. The video sink according to claim 2 , wherein, in said method, at least one gamut instance is non-convex, and any gamut hull that is used to define a gamut instance, even the non-convex gamut instance, is convex.
4. The video sink according to claim 1 , wherein said method further comprises defining of a plurality of gamut hulls, wherein at least one gamut hull of said plurality of gamut hulls is used for the definition of at least two different gamut instances.
5. The video sink according to claim 1 , wherein said method further comprises defining of a plurality of gamut instances, wherein each of them describes differently the same color gamut of the color device in the same color space.
6. The video sink according to claim 5 wherein, in said method, at least one gamut instance is convex and at least one other gamut instance is non-convex.
7. The video sink according to claim 5 wherein, in said method, among said plurality of gamut instances, some of them contains different percentages of colors of the actual color gamut.
8. The video sink according to claim 5 , wherein, in said method, among said plurality of gamut instances, some of them describe the same shape with different level of details.
9. The video sink according to claim 1 , wherein said method further comprises defining of elementary polygons, notably triangles, such that each Gamut Component is formed by the concatenation of several connex elementary polygons.
10. A video sink for color gamut mapping of colors, in a given color space, from an actual source color gamut to an actual target color gamut, the video configured to implement a method for describing either source or target, or both, actual color gamut by at least one gamut boundary description, called a gamut instance, wherein said description method comprises the steps of:
defining of at least one gamut hull as a closed surface bordering a volume, such that each gamut instance is formed by the union of the volume(s) bordered by at least one gamut hull;
defining a plurality of gamut components such that each gamut hull is formed by the concatenation of several connex gamut components, wherein each gamut component represents a surface that is meshed into a plurality of connex faces, wherein at least one gamut component of said plurality of gamut components is used for the definition of at least two different gamut hulls.
11. The video sink for color gamut mapping of colors according to claim 10 , wherein said description method comprises defining of a plurality of gamut hulls, wherein volumes of at least two of said gamut hulls of said plurality that are used to define a same gamut instance having a non-empty intersection.
12. The video sink for color gamut mapping of colors according to claim 10 , wherein, in said method, at least one gamut hull is non-convex, and any gamut hull that is used to define a gamut instance, even the non-convex gamut instance, is convex.
13. The video sink for color gamut mapping of colors according to claim 10 , wherein said description method further comprises defining of a plurality of gamut hulls, wherein at least one gamut hull of said plurality of gamut hulls is used for the definition of at least two different gamut instances.
14. The video sink for color gamut mapping of colors according to claim 10 , wherein said description method further comprises defining of a plurality of gamut instances, wherein each of definition described differently the same color gamut of the color device in the same color space and wherein at least one gamut instance is convex and at least one other gamut instance is non-convex.