A Method of the Adaptively Selected Auto-Focusing Evaluation Function According to the Image Noise Strength

This paper has done the detailed analysis on the focusing curve characteristics for several auto-focusing functions including the Brenner function, energy gradient function, average variance function and entropy function and further discussed different characteristics of the interference immunity of those functions. According to the image noise strength, different definition evaluation functions is selected to obtain the purpose of the best focusing effect. The method proposed in this paper has achieved the effective verification on the auto-focusing platform of the microscope developed independently.