www.gusucode.com > 基于马尔科夫随机场的图像分割matlab源码。包括ICM迭代条件模式求解最大后验概率算法 > code23/matlab MRF toy examples/initLocalEvidence.m

    % [nodes] = initLocalEvidence(nodes, image, p);
% Given an input binary image of the appropriate resolution, and a
% probability, p, that each pixel is flipped, initialize the local evidence
% vector coming into each node.
% october 5, 2003  wtf created.

function [nodes] = initLocalEvidence(nodes, image, p);

noisyImage = zeros(size(image));
iNode = 1;
for j = 1:size(image,2)
    for i = 1:size(image,1)
        
        % assume q is 0-1 probability of being on.
        q = image(i,j);
        
        % probability of being up is:  prob from image that it was up (q) *
        % prob that that bit wasn't flipped (1-p), plus prob from image
        % that it was down (1-q) * prob that that bit was flipped (p).
        % Similarly for prob of being down.
        nodes{iNode}.localEvidence = [q * (1-p) + (1-q) * p, (1-q) * (1-p) + q * p];
        iNode = iNode +1;
    end
end