Estimation of Depth from Defocus for Micromanipulation Based onHigh Frequency Energy Parameter Eh
ZENG Ming1, ZHANG Jian-xun1, CHEN Shao-jie1, WANG Xiang-hui2, ZHAO Xin1
1. Institute of Robotics & Information Automation System, Nankai University, Tianjin 300071, China; 2. Key Laboratory of Opto electronic Information Science and Technology, MOE, Institute of Modern Optics, Nankai University, Tianjin 300071, China
Abstract：A new method of estimating the depth information for micro manipulation is proposed. The depth information is obtained by using high-spatial frequency energy parameters of the defocused images. The algorithm consists of two steps:firstly, the depth function is derived using a sequence of calibration images with an interval of 2μm; secondly, in the practical measurement, the depth can be calculated by using this depth equation when acquiring the energy parameter of the micro-manipulator in the certain position. In the testing experiments, the effect of micro glass needle shape on calibration experiments is analyzed and overcome. This method has been successfully applied to both ranging and rapid auto focusing in the actual micro-manipulation robot named NKTY-MR.
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