Real-time measurement and analysis of translational and rotational speeds of moving objects in microscope fields

This paper describes a digital system designed for the automatic detection and measurement of the velocity of moving objects in images acquired by means of a common TV-camera mounted onto a microscope. The main characteristics of this system are the following: 1) it can perform a realtime gray level difference between two successive frames in order to detect moving objects and to suppress stationary objects (subtraction procedure); usually the delay between two successive frames varies linearly from 40 msec to 1920 msec; 2) it reduces the size of images resulting from the subtraction procedure (difference images) and stores them in the frame memory; the result of these operation, all performed in real-time, is a film of time sequences; 3) it performs an automatic labelization in order to recognize the moving microorganisms and to calculate their area in each difference image; 4) it calculates and plots the variation of the average area of the cells moving in the microscope field; 5) it completes the analysis in few seconds.