HDR IMAGE ENCODING AND DECODING METHODS AND DEVICES

摘要

To have a very efficient and in some embodiments also backwards compatible with legacy LDR display systems, apparatuses and methods relating to decoding an image encoding (LDR_CONT) corresponding to a first luminance dynamic range (R_oLDR) into a second luminance dynamic range (R_oHDR) output image (HDR_FIN), in which image encoding (LDR_CONT) are encoded pixels of an original image (HDR_ORIG) of a high dynamic range scene, the method comprising:
tone mapping with a predetermined tone mapping strategy (FL2H) at least the lumas of pixels in the image encoding (LDR_CONT) onto lumas of pixels in an intermediate image (HDR_PRED) corresponding to the second luminance dynamic range (R_oHDR); andmodifying the lumas of at least some of the pixels of the intermediate image (HDR_PRED) by multiplying them with predetermined multiplication factors, resulting in the output image (HDR_FIN) are taught.

主权项

1. A computer readable medium, that is not a transitory propagating signal or wave, the medium comprising control information for controlling an operation of a device for decoding an image encoding (LDR_CONT) corresponding to a first luminance dynamic range (R_oLDR) into a second luminance dynamic range (R_oHDR) output image (HDR_FIN), in which image encoding (LDR_CONT) are encoded pixels of an original image (HDR_ORIG) of a high dynamic range scene, the method comprising:
tone mapping with a predetermined tone mapping strategy (FL2H) at least the lumas of pixels in the image encoding (LDR_CONT) onto lumas of pixels in an intermediate image (HDR_PRED) corresponding to the second luminance dynamic range (R_oHDR); and modifying the lumas of at least some of the pixels of the intermediate image (HDR_PRED) by multiplying them with predetermined multiplication factors, the predetermined multiplication factors representing a multiplicative correction to be applied to the lumas of the at least some of the pixels of the intermediate image for obtaining a correction of the tone mapping from the first luminance dynamic range to the second luminance dynamic range, resulting in the output image (HDR_FIN).