@article {1992, title = {A variational method in image segmentation: existence and approximation result}, journal = {Acta Math. 168 (1992), no.1-2, p. 89-151}, number = {SISSA;48/89/M}, year = {1992}, publisher = {SISSA Library}, url = {http://hdl.handle.net/1963/808}, author = {Gianni Dal Maso and Jean-Michel Morel and Sergio Solimini} }