Short for High Dynamic Range Imaging, HDRI is an imaging technique that
allows for a greater dynamic range of exposure than would be obtained through
any normal imaging process. HDRI is now more commonly used for real photograph
scenes where, for example, a large range of exposures would be found between
sunlight and shadows. However, it was initially developed for use with
computer-generated graphics and images. HDRI, also called HDR (High Dynamic
Range) is a feature commonly found in high-end graphics and imaging software.
See also "An
Introduction to High Dynamic Range Imaging" on
Graphics.com.