07433514 is referenced by 25 patents and cites 10 patents.

Tone mapping a high dynamic range (HDR) image is performed by obtaining a log-norm luminance component based on a normalized logarithm of the HDR image. The log-norm luminance component is flattened (tone-compressed) using incrementally-spaced adaptation levels, which are increasingly blurrier representations of the log-norm luminance component, weighted by a diminishing factor. Visual cues are restored by injecting a proportion of values of the log-norm luminance component, applying histogram tail clipping, and applying a sigmoid curve mapping, to create a restored luminance component. A tone-compressed image is obtained by mapping luminance of the HDR image using the restored luminance component and adjusting saturation of the mapped HDR image.

Title
Tone mapping of high dynamic range images
Application Number
11/180768
Publication Number
7433514 (B2)
Application Date
July 13, 2005
Publication Date
October 7, 2008
Inventor
Rocklin J Sloan
San Jose
CA, US
Agent
Fitzpatrick Cella Harper & Scinto
Assignee
Canon Kabushiki Kaisha
JP
IPC
G06K 9/00
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