Image processing and magnetic material have two similar theoretical structures with each other. The similarities are very simple. They are constructed from many elements. The many elements interact with each other. As you know, the classical spin systems have a lot of spins and each spin interacts with the neighboring spins. The ordered state is determined from interactions and external fields. On the other hand, images are constructed from a lot of pixels. Output of each pixel are determined from the input values of the neighboring pixels. Output images are determined from a priori information and given data. Thus, the conventional image processing theory and the classical spin system have the similar structure. In the classical spin system, the phase transition occurs at a critical temperature. Below the critical temperature, the classical spin system has a disordered state, for example Paramagnetic state. Above the critical temperature, the classical spin system has an ordered state, for example Ferromagnetic state. In statistical mechanics, many researchers investigate the classical spin systems near the critical temperature. Near the critical temperature, fluctuation is enhanced. Statistical mechanics has a lot of techniques to treat fluctuation near the critical temperature. On the other hand, it is difficult for conventional filters to treat fluctuation in data systematically. In the present project, the statistical mechanical strategies are employed to treat fluctuation in data in image processing.