Patent ID: 8218625
Filing Date: 2012-07-10
Classification: G06T,G09G,H04N

Abstract:
1. A method for encoding high dynamic range image data having an initial dynamic range, the method comprising: obtaining tone map data corresponding to the high dynamic range image data, the tone map data having a reduced dynamic range lower than the initial dynamic range; processing the high dynamic range image data and the tone map data by a machine to yield ratio data, the ratio data comprising ratios of values in the high dynamic range image data and corresponding values in the tone map data; generating high dynamic range information based on the ratio data; generating tone map information based on the tone map data; and, storing the high dynamic range information and the tone map information in a data structure; wherein generating the high dynamic range information comprises applying to the ratio data a correction function, the correction function based on the tone map data; the correction function is of the form: or a mathematical equivalent thereof, where: L(TM) is the luminance for a pixel in the tone map data and L(TM σ is a measure of variance in the ratio of L(TM) to L(TM