Summary: | 碩士 === 國立中興大學 === 機械工程學系 === 91 === In this thesis, new approaches of the computer vision techniques such as the optimal threshold, the auto focusing, the edge detection, and the image expansion are investigated.
For the optimal threshold, the piecewise searching method that detects the threshold according to the histogram of the gray-level distribution is adopted. Experimental results show that the misjudge problems of the conventional methods is improved. It is also found that the worse the out-of focus is, the lower the optimal threshold is. This physical phenomenon is adopted to develop the new auto focusing method. Less complexity is the main advantage of the proposed auto focusing scheme.
For better edge detection, we use the Lagrange polynomials to build a 2D Lagrange mask such that the required computation time is reduced and the subpixel edge can be directly estimated. The 2D Lagrange edge detection method along with the bipolar sigmoid function is then used to modify the expended edge such that the obscure expansion problem is decreased.
To verify the performance of these new approaches, an auto focusing platform which consists of a linear slider and a step motor, a high resolution couple charged device (CCD), and an image processing software that is written in Borland C++ Builder, are brought together to build a complete image inspection system. The image processing tasks of the cell culture in tissue engineering demonstrate that the proposed image inspection system can be successfully applied to the biomedical analysis problems.
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