The use of infra-red light in the investigation of works of art is, of course, a well established procedure in conservation and art historical studies. Besides the usual techniques of infra-red photography or the use of an infra-red vidicon to scan works for underdrawings, inscriptions or underpaintings, in recent years the digitization of these images and subsequent manipulation of the images by computer software has expanded our abilities to understand more fully and in greater detail these underlying layers. This lecture will explore some of these possibilities in the context of modern paintings. Various image processing techniques such as contrast enhancement and histogram modifications will be discussed in some particular instances where they can extract more information from the digitized images.