System identification-based depth information extracting from microscopic image

A new method of extracting depth information from microscopic image is put forward and implemented in this paper. Firstly, the problem of extracting depth information by image processing is transferred into identification of microscopic point spread parameter. Secondly, a new method of identifying microscopic point spread parameter is put forward, the corresponding experiment is completed and the mapping between microscopic point spread parameter and Z coordinates is set up. Thirdly the method of extracting depth information from microscopic image is given, in the condition of 40× microscope, the experimental accuracy is 2.6 μm and it takes 3-5 s to compute a depth value; this method achieves the level of on-line application both in accuracy and efficiency.