Camera and visual veiling glare in HDR images

Many labs are studying High Dynamic Range (HDR) image capture and display. HDR images are superior to conventional images. This paper describes the long history of HDR imaging from Renaissance paintings to modern digital imaging. Then it reviews experiments that measure camera and human responses to calibrated HDR test targets. It describes tests showing that image dynamic range is limited by the camera’s and the eye’s veiling glare, testing its physical limits and evaluating the role of accurate reproduction of luminance in imaging. Glare is an uncontrolled spread of an image-dependent fraction of scene luminance caused by unwanted scattered light in the camera and in the eye. The paper discusses why HDRI is better than conventional imaging, despite the fact the reproduction of luminance is inaccurate.