Training Set The training set was composed by 8 images, and the distance metric was learned from the white paths over the images, as shown at left columns. At center, we show the segmentation results of the Mumford-Shah algorithm when using the simple Euclidean distance to compute the similarity between the color vectors. At right, the segmentation results of the proposed approach using the training set defined at left column. Original Image and training set defined by the white paths Euclidean Based Proposed