author = "Torre{\~a}o, Jos{\'e} R. A.",
                title = "Natural photometric stereo?",
            booktitle = "Anais...",
                 year = "1996",
               editor = "Velho, Luiz and Albuquerque, Arnaldo de and Lotufo, Roberto A.",
                pages = "95--102",
         organization = "Simp{\'o}sio Brasileiro de Computa{\c{c}}{\~a}o Gr{\'a}fica e 
                         Processamento de Imagens, 9. (SIBGRAPI)",
            publisher = "Sociedade Brasileira de Computa{\c{c}}{\~a}o",
              address = "Porto Alegre",
             abstract = "The human brain seems to have the ability of inferring shape from 
                         the binocular fusion of some kinds of monocular images. Recently, 
                         we have observed that photometric stereo (PS) images, which are 
                         monocular images obtained under different illuminations, produce a 
                         vivid impression of depth, when viewed under a stereoscope. 
                         Lately, we have found that the same is true of pairs of images 
                         obtained in different spectral bands. Employing an optical-flow 
                         based photometric stereo algorithm on a type of {"}colour 
                         separated images{"}, which have been so produced as to emulate the 
                         kinds of records generated by the photosensitive cells in the 
                         human retina, we have been able to obtain depth estimates from 
                         them. This has led us to speculate on the possibility that a 
                         process similar to PS could work on the human visual system. Here 
                         we present our claim for a natural photometric stereo process, 
                         invoking some physical and biological arguments, along with 
                         experimental results, that could support it.",
  conference-location = "Caxambu",
      conference-year = "29 out. - 1 nov. 1996",
                 isbn = "85-244-0103-6",
             language = "en",
         organisation = "SBC - Sociedade Brasileira de Computa{\c{c}}{\~a}o; UFMG - 
                         Universidade Federal de Minas Gerais",
                  ibi = "83LX3pFwXQZW44Lb/cMSux",
                  url = "",
           targetfile = "a20.pdf",
                 type = "Vis{\~a}o por Computador",
        urlaccessdate = "2021, Dec. 09"