Disparity calculating method and stereo matching system thereof

A stereo matching system, comprising:

• a global disparity storing module, for storing a previous disparity matrix and a global disparity matrix of a previous frame;
• a previous block disparity storing module, for storing a previous block disparity matrix between a first image and a second image;
• a current block disparity storing module, for storing a local disparity matrix;
• a global disparity calculating module, coupled to the global disparity storing module, for calculating a global energy matrix according to the first image, the second image and the previous disparity matrix and calculating the global disparity matrix according to the global energy matrix and a first stereo matching algorithm;
• and
• a local disparity calculating module, coupled to the global disparity storing module, the previous block disparity storing module and the current block disparity storing module, for calculating a local energy matrix between a first image block of the first image and a second image block of the second image according to the first image block, the second image block, the previous local disparity matrix and the global disparity matrix and calculating the local disparity matrix between the first image block and the second image block according to the local energy matrix and a second stereo matching algorithm.