The use of a spatially dependent external field is introduced as an extension of more regular Markov random fields models with interaction terms only. This external field is used to model prior knowledge about the global image structure. An application to recognition of the spleen from three-dimensional X-ray CT scences is described.
A relaxation method for image segmentation using a spatially dependent stochastic model
N. Karssemeijer
Pattern Recognition Letters 1990;11(1):13 - 23.