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 of transforming dynamic metadata comprising:
receiving, by at least one computer processor or integrated circuit, source content metadata for a first color volume transformation model, the source content metadata associated with content;
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
perceptually 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; and
rendering, by the at least one computer processor or integrated circuit, the content for the second color volume transformation model.
2. The method of claim 1 further comprising generating content metadata of the second color volume transformation model, wherein content metadata of the second color volume transformation model includes at least one knee point and an anchor for a Bézier curve.
3. The method of claim 2 , 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.
4. The method of claim 1 further comprising generating content metadata of the second color volume transformation model, wherein 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.
5. The method of claim 4 , wherein the source content metadata of the first color volume transformation model includes at least one knee point and an anchor for a Bézier curve.
6. The method of claim 1 , wherein the mapping is performed in at least one of real-time and near real-time.
7. The method of claim 1 , wherein said mapping is performed in a networking cloud.
8. The method of claim 1 , wherein said mapping is performed off-line.