High Dynamic Range Rendering
High Dynamic Range Rendering (HDRR), sometimes also called High Dynamic Range Lighting, is a special Image Based Lighting (IBL) technique in 3d computer graphics to illuminate a virtual scene using a spherical image instead of standard light shapes such as point lights, area lights and spot lights. Here, the luminance distribution of the image is used to model the light distribution of the 3d scene. Standard images with 256 different levels for each color channel (RGB) are not sufficient to achieve realistic looking results. Therefore, images have to be used with a very large dynamic range. Those images can be produced by taking standard (low dynamic range) images with different levels of exposure, which are combined to an HDR image (HDRI):
Obviously, HDR images cannot be displayed on standard monitors with their limited dynamic range of 3*256 different luminance values. Therefore, a Tone Mapping technique has to used to convert HDR images back to low dynamic range images while preserving the image details and color appearance of the original HDRI.
HDRR = HDRI + IBL + Tone mapping