HDR PhotoStudio is a discontinued high dynamic range (HDR) graphics application developed by Unified Color for the Windows and macOS operating systems. In addition to being a HDR-merge application, HDR PhotoStudio offered a set of image editing operations that worked in its dynamic range, human color range (gamut), and in high precision. It also had a Color Integrity feature that enabled preserving an image's color tone during image editing operations — for example changing an image's contrast would not change its chromatic data. This problem is usually referred to as "color shift".