Development of three-dimensional measuring system for particle movement and the application for environmental inspection.

点击翻译按钮获取中文摘要

A new technique to measure the instantaneous three-dimensional movement of particle is developed. By introducing a refractor on the TV camera lens, the image of tracer particle is displaced corresponding to the distance between the TV camera and tracer particle. Upon rotating the refractor at high speed during the TV camera exposure, spiral streaks of moving particles appear on an image since the circular shift is added to the movement of tracer particles. Each spiral streak contains three-dimensional information of the moving particle since the size of the streak is inversely proportional to the distance of the particle from the camera. The location and size of the spiral streak in the image are related to the three-dimensional location of the particle, and the pitch and size variation of the streak are related to the three-dimensional velocity of the tracer particle.In the case that many particles are existed in a frame, some annular streaks of measuring points overlap each other. In order to extract each annular streak from overlapped streaks, lines in the direction of edge normal are generated. Normal lines at the segment of an annular streak accumulate in the 2-dimensional parameter space. Since the annular streak has concentric segment, their normal lines converge at the center of the annular streak. The center of the each annular streak can be extracted by finding the peak generated in the parameter space. This procedure enables fast and efficient analysis of annular streaks. This technique is applied also for the analysis of spiral streaks.Since small organisms are easy to be influenced by the circumstances, the quantitative inspection can be executed by measuring the movement of small organism. In this study, the measuring system for the movement of small organism is developed using the image processing.