High-speed focusing of cells using depth-from-diffraction method

This paper proposes a new autofocusing method for microbiological specimens, such as cells. The proposed focusing method used a quick focus estimation named "depth from diffraction", based on a diffraction pattern in a defocused image of a biological specimen. Since this method can estimate the focal position of the specimen from only a single defocused image, it can easily realize high-speed autofocusing. To demonstrate the proposed method, continuous focusing was applied to focus tracking of a swimming paramecium, in combination with two-dimensional tracking. This allowed three-dimensional tracking of the paramecium for 75 s to be successfully demonstrated

[1]  M. Ishikawa,et al.  A CMOS vision chip with SIMD processing element array for 1 ms image processing , 1999, 1999 IEEE International Solid-State Circuits Conference. Digest of Technical Papers. ISSCC. First Edition (Cat. No.99CH36278).

[2]  Masatoshi Ishikawa,et al.  1 ms column parallel vision system and its application of high speed target tracking , 2000, Proceedings 2000 ICRA. Millennium Conference. IEEE International Conference on Robotics and Automation. Symposia Proceedings (Cat. No.00CH37065).

[3]  H. Berg.  How to track bacteria. , 1971, The Review of scientific instruments.

[4]  W. D. Nesse,et al.  Introduction to optical mineralogy , 1986 .

[5]  J. Goodman.  Introduction to Fourier optics , 1969 .

[6]  Koichi Hashimoto,et al.  Two-dimensional tracking of a motile micro-organism allowing high-resolution observation with various imaging techniques , 2005 .

[7]  A W Smeulders,et al.  Robust autofocusing in microscopy. , 2000, Cytometry.