@conference {tardon1999markov, title = {Markov random fields and the disparity gradient constraint applied to stereo correspondence}, booktitle = {Image Processing, 1999. ICIP 99. Proceedings. 1999 International Conference on}, volume = {3}, year = {1999}, pages = {901{\textendash}905}, publisher = {IEEE}, organization = {IEEE}, author = {Lorenzo J Tard{\'o}n-Garc{\'\i}a and Javier Portillo-Garcia and Carlos Alberola-Lopez} }