Patent ID: 9299317
Filing Date: 2016-03-29
CPC Classification: G06T,G09G

Claim Text:
1. A method comprising: converting luminance values in an input high dynamic range (HDR) image into a logarithmic domain; applying a global ratio operator to the luminance values in the logarithmic domain derived from the input high dynamic range (HDR) image to generate a high resolution gray scale ratio image in the logarithmic domain comprising luminance ratio values; generating, based at least in part on the high resolution gray scale ratio image in the logarithmic domain, at least two different gray scale ratio images, merging the at least two different gray scale ratio images to generate a local multiscale gray scale ratio image that comprises a weighted combination of the at least two different gray scale ratio images, each being of a different spatial resolution level; wherein the local multiscale gray scale ratio image is obtained using recursive processing; using ratio values in the local multiscale gray scale ratio image with the luminance values in the logarithmic domain derived from the input HDR image to generate a tone-mapped gray scale image; wherein the tone-mapped gray scale image comprises a fixed-point grayscale image with the same spatial dimensions as the spatial dimensions of the input HDR image; and computing a reference maximum over the tone-mapped gray scale image such that a percentage of pixels that lie outside a color gamut are not more than a threshold.