1. A method for processing a tissue image of stained tissue, the method comprising: generating a matrix of feature vectors, wherein each feature vector corresponds to a respective pixel of the tissue image and describes color and texture features of the respective pixel, wherein the stained tissue depicted in the tissue image is stained such that each color present in the stained tissue corresponds to a different tissue type; selecting a subset of feature vectors from the matrix of feature vectors; deriving a set of colors and textures using the tissue image and the subset of feature vectors; and generating an initial segmented tissue image using the set of colors and textures and the tissue image; and merging regions within the initial segmented tissue image to generate a final segmented image having a number of segments corresponding to the number of tissue types in the tissue image, wherein the number of segments is predetermined based on the number of different tissue types in the stained tissue.