Patent ID: 8737736

Claim:
A method for converting a first image represented by HDR pixels having a predetermined dynamic range, said first image comprising a plurality of tiles each including a two-dimensional array of a plurality of said HDR pixels, into a second image with corresponding LDR pixels having a lower dynamic range, the method including: performing a local tone mapping on each HDR pixel of said first image using a local transfer function for converting HDR pixels into LDR pixels having a locally tone mapped value, said local transfer function being derived from at least one image parameter of said HDR pixels in a plurality of tiles proximate to a tile containing a particular HDR pixel, wherein the number of the plurality of tiles proximate to said tile containing the particular HDR pixel depends on content of a scene that has been captured by said first image; performing a global tone mapping on each HDR pixel using a global transfer function for converting HDR pixels into LDR pixels having a globally tone mapped value, said global transfer function being derived from an average value of said at least one image parameter of all said HDR pixels; deriving a final value for each LDR pixel by weighting said locally and globally tone mapped pixel values using a first weighting factor applied to each said locally tone mapped LDR pixel value and a second weighting factor applied to each said globally tone mapped LDR pixel value and combining said weighted locally and globally tone mapped LDR pixel values; and storing one or more derived final values in a storage device.