Beta scale dynamic display mapping
An input image to be coded into a video signal and a target image are received. The input image and the target image depict same visual content. One or more beta scaling method indicators and one or more sets of one or more beta scale parameters are generated. The one or more beta scaling method indicators indicate one or more beta scaling methods that use the one or more sets of beta scale parameters to perform beta scaling operations on the input image to generate a reconstructed image to approximate the target image. The input image, along with the one or more beta scaling method indicators and the one or more sets of beta scale parameters, is encoded into the video signal for allowing a recipient device of the video signal to generate the reconstructed image.
1 . A method comprising:
receiving an input image to be coded into a video signal and a target image, wherein the input image and the target image depict same visual content;
generating one or more beta scaling method indicators and one or more sets of one or more beta scale parameters, wherein the one or more beta scaling method indicators indicate one or more beta scaling methods that use the one or more sets of one or more beta scale parameters to perform beta scaling operations on the input image to generate a reconstructed image to approximate the target image and wherein the one or more beta scaling methods and/or the one or more sets of one or more beta scale parameters are individually selected for scaling pixel values or codeword values in different spatial regions of the input image;
encoding the input image, along with the one or more beta scaling method indicators and the one or more sets of one or more beta scale parameters, into the video signal for allowing a recipient device of the video signal to generate the reconstructed image.
2 . The method of claim 1 , wherein the reconstructed image and the target image are same in one or more of: dynamic range, color gamut, spatial resolution, or color space.
3 . The method of claim 1 , wherein the reconstructed image represents one of: a standard dynamic range image, a high dynamic range image, wherein the high dynamic range is wider than the standard dynamic range, or a display mapped image that is optimized for rendering on a target image display.
4 . The method of claim 1 , wherein the input image includes two or more different spatial regions; wherein the two or more different spatial regions are differently scaled with two or more different combinations of beta scaling methods and beta scaling parameters formed by the one or more beta scaling methods and the one or more sets of one or more beta scale parameters.
5 . The method of claim 1 , wherein an overall beta scaling indicator indicating a beta scaling method to be applied to all of the different spatial regions is generated.
6 . The method of claim 1 , wherein at least a part of the one or more beta scaling method indicators and the one or more sets of one or more beta scale parameters is carried in a beta scale map and wherein at least a part of the one or more beta scaling method indicators and the one or more sets of one or more beta scale parameters is encoded as one or more of: image-level image metadata portions, sequence-level image metadata portions, or scene-level image metadata portions.
7 . The method of claim 1 , wherein the one or more sets of one or more beta scale parameters defined for a spatial region of the input image represent scaling values to be applied to coded component codewords of each pixel in the same spatial region in a coded component image of the coded input image to generate a reconstructed component codeword of a respective pixel in the same spatial region in a reconstructed component image of the reconstructed image.
8 . The method of claim 7 , wherein the scaling values are multiplied in a non-logarithmic representation or are added in a logarithmic representation to the coded component codewords of each pixel in the same spatial region.
9 . The method of claim 7 , wherein the scaling values are combined with or without weighting factors.
10 . The method of claim 1 , wherein the beta scaling operations include one or more of: multiplications and/or additions, non-linear scaling operations, Look-Up-Table (LUT) based scaling, simple scaling with scaling factors, or applying one or more codeword mapping to map codewords of the input image to generate corresponding codeword of the reconstructed image.
11 . The method of claim 10 , wherein the one or more codeword mapping includes one of: a codeword mapping preconfigured with the recipient device, a codeword mapping not delivered with the video signal, or a codeword mapping identified by one or more of a beta scaling method indicator in the one or more beta scaling method indicators or a set of beta scale parameters in the one or more sets of one or more beta scale parameters.
12 . The method of claim 1 , wherein the input image is encoded in a base layer of the video signal.
13 . The method of claim 1 , wherein at least a part of the one or more sets of one or more beta scale parameters represents scaling factors.
14 . The method of claim 1 , wherein the beta scaling operations are performed in place of one or more of: global tone mapping, local tone mapping, display mapping operations, color space conversion, linear mapping, or non-linear mapping.
15 . The method of claim 1 , wherein the beta scaling operations include one or more of: single-channel mapping operations each of which maps codewords in a single color channel of an input color space to reconstructed codewords in a single color channel of an output color space, or cross-channel mapping operations each of which maps codewords in two or more color channels of an input color space to reconstructed codewords in a single color channel of an output color space.
16 . The method of claim 1 , wherein the spatial regions spatially demarcate the input image and the target image.
17 . An apparatus performing the method as recited in claim 1 .
18 . A non-transitory computer readable storage medium, storing software instructions, which when executed by one or more processors cause performance of the method recited in claim 1 .
19 . A method comprising:
decoding, from a video signal, an input image;
decoding, from the video signal, one or more beta scaling method indicators and one or more sets of one or more beta scale parameters, wherein the one or more beta scaling method indicators indicate one or more beta scaling methods;
performing beta scaling operations on the input image as specified with the one or more beta scaling method indicators and the one or more sets of one or more beta scale parameters to generate a reconstructed image, wherein the one or more beta scaling methods and/or the one or more sets of one or more beta scale parameters are individually selected for scaling pixel values or codeword values in different spatial regions of the input image;
causing a display image derived from the reconstructed image to be rendered on a target image display.
20 . The method of claim 19 , wherein the target image display represents one of: a RGB image, an YCbCr image, or an image represented in another color space.