A new bond percolation-based approach is presented to determine the clique potential parameters of a Gibbs-Markov random field (GMRF) model used in image segmentation. Previously, experimentally determined fixed values were used for these parameters independent of the underlying image. Using the proposed approach, these parameters are now derived as a function of local characteristics of the image under consideration. An additional salient feature of this method is its suitability for a renormalization group approach to multi-scale description of the clique potential parameters. >