INVERSE TONE MAPPING WITH ADAPTIVE BRIGHT-SPOT ATTENUATION

• Main Authors: Poirier, Guillaume, Plissonneau, Frederic, Cauvin, Laurent
• Format: Patent
• Language: English
• Published: 24.08.2023
• Subjects: CALCULATING; COMPUTING; COUNTING; IMAGE DATA PROCESSING OR GENERATION, IN GENERAL; PHYSICS

A method for inverse tone mapping by obtaining a gain function, called initial gain function, of a first inverse tone mapping function; if an analysis of a current image shows that at least a pixel of the current image with a luminance value at least equal to a luminance value depending of a predetermined percentage of the pixels of the current image have an expanded luminance value resulting from an application of the first ITM function to the current image higher than a target value, applying a second ITM function to the current image, the second ITM function corresponding to the first inverse tone mapping function in which the gain function has been replaced by a modified gain function derived from the initial gain function in which a gain provided by the initial gain function is attenuated by an attenuation function, said attenuation function being weighted by a weighting factor controlling a strength of the attenuation, the weighting factor depending on a statistical distribution of luminance values in an histogram of the current image between a maximum luminance value and the luminance value depending of the predetermined percentage.