author = "Queiroz, Ricardo L. de",
          affiliation = "{Universidade de Brasilia}",
                title = "Improved Reversible Mapping from Color to Gray",
            booktitle = "Proceedings...",
                 year = "2007",
               editor = "Falc{\~a}o, Alexandre Xavier and Lopes, H{\'e}lio C{\^o}rtes 
         organization = "Brazilian Symposium on Computer Graphics and Image Processing, 20. 
            publisher = "IEEE Computer Society",
              address = "Los Alamitos",
             keywords = "colro mapping, texturization.",
             abstract = "In the reversible conversion of color images to gray ones, colors 
                         are mapped to textures and from the textures the receiver can 
                         recover the colors, i.e. one may print a color image with a black 
                         and white printer and, at a later time, recover colors. Such a 
                         method was originally devised using the wavelet transform and 
                         replacing high-frequency subbands by subsampled chrominance 
                         planes. Here, we propose to improve the original method thorugh 
                         the use of a largely redundant representation of the chrominance, 
                         with multiple embedding into subbands of a general subband 
                         transform. Our results point to minimization of the variance of 
                         the error caused by noise when the chrominance is replicated into 
                         many subbands and not linearly combined. Derived noise bounds 
                         guide us on how many subbands to embed the chrominance. 
                         Experimental results were carried for multiple noise levels, 
                         models, transform sizes, and number of embedding subbands, 
                         demonstrating the theoretical analysis and the method's potential. 
  conference-location = "Belo Horizonte",
      conference-year = "Oct. 7-10, 2007",
             language = "en",
           targetfile = "colortobw-subbands-sibgrapi.pdf",
        urlaccessdate = "2021, Jan. 19"