Video analysis of motion

Abstract

Motion analysis wherein a camera (14) converts an image of a body having illuminated markers placed thereon into plural image frames. A preprocessor (26) receives plural image lines and detects the occurrence of each marker in each line when a pixel amplitude exceeds a threshold, and an offset value representing the difference therebetween is added to a running total of values for the detected marker. Similarly, the offset is used to calculate moment for each pixel in each marker based on pixel line position. The calculated moment is added to a running total for the detected marker. Amplitude and moment sums for each pixel series for each marker in each line are passed to a processor which groups the amplitude and moment sums for each marker together. The grouped values are used to calculate a centroid value for each marker in real time, the result provided to a CPU.