Detection of Non-Stationary Photometric Perturbations on Projection   Screens
  Interfaces based on projection screens have become increasingly more popular in recent years, mainly due to the large screen size and resolution that they provide, as well as their stereo-vision capabilities. This work shows a local method for real-time detection of non-stationary photometric perturbations in projected images by means of computer vision techniques. The method is based on the computation of differences between the images in the projector's frame buffer and the corresponding images on the projection screen observed by the camera. It is robust under spatial variations in the intensity of light emitted by the projector on the projection surface and also robust under stationary photometric perturbations caused by external factors. Moreover, we describe the experiments carried out to show the reliability of the method. 
Miguel Casta\~neda-Garay, Oscar Belmonte-Fern\'andez, Hebert   P\'erez-Ros\'es, Antonio Diaz-Tula
cs.CV