Abstract: The invention relates to a method for encoding HDR images, of the type wherein the HDR image is encoded in a first data stream containing a LDR image with colour range lower than that of the HDR image, and in a second data stream containing a residual image obtained from the HDR image and from the LDR image.

Abstract: This document describes methods and devices for encoding and decoding images and videos, including encoding high dynamic range images, both static images and video frames. In aspects, a high dynamic range image is acquired, a dynamic range value of the high dynamic range image and an image average luminance value of the high dynamic range image is calculated, the high dynamic range image is converted to a low dynamic range, and the low dynamic range is compressed. In aspects, a low dynamic range image is decoded back into a high dynamic range image.

Abstract: A method for processing image and video data, comprising providing high dynamic range image data (HDR) and a corresponding low dynamic range image data (LDR). The LDR image is encoded in a legacy code stream, while a residual code stream is generated and encoded containing data necessary for the reconstruction of the HDR image in a decoding phase. To generate the residual code stream, LDR image data are processed so as to obtain a processed LDR* image, then a component data of the HDR image and a corresponding component of the processed LDR* image are selected and residual data of the selected component data are calculated by dividing the component of the processed LDR* image data by the component of the HDR image data. The residual data of the selected component are scaled into the range of values comprised between 0 and 1 and are then encoded in a residual code stream. A decoding method is also disclosed which allows reconstruction of an HDR image from a legacy code stream and a residual data code stream.

Abstract: The invention relates to a method for encoding HDR images, of the type wherein the HDR image is encoded in a first data stream containing a LDR image with colour range lower than that of the HDR image, and in a second data stream containing a residual image obtained from the HDR image and from the LDR image.

Abstract: The invention relates to a method for encoding high dynamic range images, both static images and video frames. The method comprises the steps of: a) acquiring a high dynamic range image in floating point format; b) calculating the dynamic range of the acquired image; c) calculating the image average luminance; d) calculating a parameter dynamic_range by adding to or subtracting from the dynamic range value calculated at step b) a predetermined value, the addition or subtraction of such predetermined value depending on image average luminance calculated at step c); e) multiplying the values of the pixels of the acquired image by a factor equal to 2?dynamic_range; f) raising to a power equal to 1.0/(2.

Abstract: A method for processing image and video data, comprising providing high dynamic range image data (HDR) and a corresponding low dynamic range image data (LDR). The LDR image is encoded in a legacy code stream, while a residual code stream is generated and encoded containing data necessary for the reconstruction of the HDR image in a decoding phase. To generate the residual code stream, LDR image data are processed so as to obtain a processed LDR* image, then a component data of the HDR image and a corresponding component of the processed LDR* image are selected and residual data of the selected component data are calculated by dividing the component of the processed LDR* image data by the component of the HDR image data. The residual data of the selected component are scaled into the range of values comprised between 0 and 1 and are then encoded in a residual code stream. A decoding method is also disclosed which allows reconstruction of an HDR image from a legacy code stream and a residual data code stream.