Area Surveying Through Image Analysis
Original Publication Date: 1985-Mar-01
Included in the Prior Art Database: 2005-Feb-18
Many business applications require detection of object motions within images captured by video cameras. This function could be performed by capturing and recording pictures and by digitally processing the stored video signal. The video signal provided by a camera is first converted into digital information. Consecutive (e.g., at times T and T-1) digitally converted images are then correlated. Assume that image at time T comprises N samples Xn with n = 1, 2, ..., N, and that the previous image, i.e., taken at T-1, includes N samples Yn . One may derive an autocorrelation coefficient Q therefrom: (Image Omitted) Consequently, for the image at time T, the processor provides scalar Q(T): (Image Omitted) For Q(T) small or null, the two images do not correlate linearly and, consequently, a change (motion) occurred.