| 摘要 |
PURPOSE:To measure the speed of a moving body on real-time basis by calculating the time difference and distance between two points of time where time variation in the length of an overlap of an optionally set closed curve and the track of a body image is maximum. CONSTITUTION:An image of the moving body is caught by a television camera 4 and the closed curve 2 is set on a screen by a closed curve setter 5 to extract a video signal on the curve 2. A binary coding circuit 7 codes the signal into a binary signal of ''1'' and ''0'' according to whether the body is present or absence and divides the resulting signal to systems S1-S3. The system S1 is inputted to a superposing device 10, which ORs picture elements of the input signal with those of a picture element array superposed at last time to generates an OR output. The output shows the overlap of the track of the object image 3 and the curve 2. The output of the supersposing device 10 is inputted to an adder 11 to sum up numbers of all picture elements, and thus the number of picture elements where the curve 2 overlaps the track of the object image 3; and a decision device 12 detects an abrupt increase in the number of picture elements and sends it output to a speed operator 5. The operator 15 stores the time and numbers of picture elements on the curve 2 which overlap the object image 3 newly and operates the speed. |
