Max-planck-gesellschaft Zur F&#xf6;rderung Der Wissenschaften E. V.

Grzegorz Krawczyk

Hans-Peter Seidel

Karol Myszkowski

Rafal Mantiuk

Alexander Efremov

A method for encoding high dynamic range (HDR) images involves providing a lower dynamic range (LDR) image, generating a prediction function for estimating the values for pixels in the HDR image based on the values of corresponding pixels in the LDR image, and obtaining a residual frame based on differences between the pixel values of the HDR image and estimated pixel values. The LDR image, prediction function and residual frame can all be encoded in data from which either the LDR image of HDR image can be recreated.

High dynamic range codecs

A method for encoding high dynamic r&#xe4;nge (HDR) images involves providing a lower dynamic r&#xe4;nge (LDR) image, generating a prediction function for estimating the values for pixels in the HDR image based on the values of corresponding pixels in the LDR image, and obtaining a residual frame based on differences between the pixel values of the HDR image and estimated pixel values. The LDR image, prediction function and residual frame can all be encoded in data from which either the LDR image of HDR image can be recreated.

A method and apparatus for encoding high dynamic range video by means of video compression is shown. The method comprises the steps of providing high dynamic range  (HDR) tristimulus color data (XYZ) for each frame of the video and threshold versus intensity data for a human observer; constructing a perceptually conservative luminance transformation from continuous luminance data (Y) to discrete values (L) using said threshold versus intensity data for the human observer; transforming the HDR tristimulus color data into perceptually linear color data of three color channels (L, u', v&#x2032;) for obtaining visually lossless compressed frames; estimating motion vector of said consecutive frames of the video and compensating the difference of the tristimulus color data for performing an inter-frame encoding and an inter-frame compression; transforming the compensated differences of the tristimulus color data to frequency space data; quantizing said frequency space data; variable-length encoding of the quantized frequency space data and storing or transmitting a stream of visual data resulting from the encoded quantized frequency space data.

Growing community of inventors

Saarbrucken, Germany

Grzegorz Krawczyk