Transformation of dynamic metadata to support alternate tone rendering
An existing metadata set that is specific to a color volume transformation model is transformed to a metadata set that is specific to a distinctly different color volume transformation model. For example, source content metadata for a first color volume transformation model is received. This source metadata determines a specific color volume transformation, such as a sigmoidal tone map curve. The specific color volume transformation is mapped to a color volume transformation of a second color volume transformation model, e.g., a Bézier tone map curve. Mapping can be a best fit curve, or a reasonable approximation. Mapping results in metadata values used for the second color volume transformation model (e.g., one or more Bézier curve knee points and anchors). Thus, devices configured for the second color volume transformation model can reasonably render source content according to received source content metadata of the first color volume transformation model.
1. A computer or integrated circuit implemented method for enhanced reproduction of high dynamic range content, the method comprising:
receiving, by at least one computer processor or integrated circuit, source content metadata for a first color volume transformation model;
determining, by the at least one computer processor or integrated circuit, a first transfer curve for the first color volume transformation model based on the received source content metadata; and
mapping, by the at least one computer processor or integrated circuit, the first transfer curve of the first color volume transformation model to a second transfer curve of a second color volume transformation model, the mapping comprising a curve fitting of the first transfer curve of the first color volume transformation model to the second transfer curve of the second color volume transformation model; and
wherein said mapping generates content metadata for the second color volume transformation model.
2. The method of claim 1 , wherein the curve fitting comprises a best fit match of the first transfer curve of the first color volume transformation model to the second transfer curve of the second color volume transformation model and wherein said first transfer curve is a first tone transfer curve and said second transfer curve is a second tone transfer curve.
3. The method of claim 1 , wherein the curve fitting comprises a perceptually reasonable match of the first transfer curve of the first color volume transformation model to the second transfer curve of the second color volume transformation model and wherein said first transfer curve is a first tone transfer curve and said second transfer curve is a second tone transfer curve.
4. The method of claim 1 , wherein the generated content metadata of the second color volume transformation model includes at least knee point and an anchor for a Bezier curve.
5. The method of claim 4 , wherein the source content metadata of the first color volume transformation model includes minimum, average and maximum color component values for at least one of a picture and a delineated group of pictures.
6. The method of claim 1 , wherein the generated content metadata of the second color volume transformation model includes minimum, average and maximum color component values for at least one of a picture and a delineated group of pictures.
7. The method of claim 6 , wherein the source content metadata of the first color volume transformation model includes at least one knee point and an anchor for a Bezier curve.
8. The method of claim 1 , wherein the mapping comprises a color saturation mapping.
9. The method of claim 1 , wherein the mapping comprises a luminance mapping.
10. The method of claim 1 , wherein the mapping comprises a tone mapping.
11. The method of claim 1 , wherein the mapping is performed in at least one of real-time and near real-time.
12. The method of claim 1 , wherein the mapping is performed in a networking cloud.
13. The method of claim 1 , wherein the mapping is performed off-line.