A Real-Time for Classification of Moving Objects
Introduction Developed a software system by a static to detect and track moving object Main components: 1.initialization 2.adaptive update of a background model 3.detection and tracking of moving objects 4.extraction of feature vectors and classification
Change Detection and Background Modelling Temporal differencing -adaptive to changes in the environment, but does not detect the entire object Background subtraction - provide more reliable information about moving object but requires more complex processing
Background Initialization Background initialization is done in the first 1-2 seconds. First, initialize the background image by the first frame - Create a binary mask - use the Eucledian metric for measuring the distance
Looking at the binary mask created by thresholding the difference between and Updating the background pixels as:
The process stops when the number of remaining suspicious pixels After the process is finished the uninitialized background pixel set their values from the last frame
Background Adaptation An adaptive update of the background due to the two main reasons -changes caused by moving objects -changes due to illumination
Target Detection and Tracking Target detection is performing using the background subtraction. The target is partitioned into horizontal strips and the color table entries hold average RGB values for each strip The number of strips depends on target size
The color table is used for defineing an individual threshold for each pixel and every target. is the threshold image is the target color table of size
Feature Vectors and Classification The ratio between perimeter and area is commonly used as the object shape characteristic The ratio between the lengths of the vertical and horizontal axes of the ellipse fitted to the object contour
Star skeleton is created by connecting the center of mass of the moving object with contour points corresponding to the local maxima of the distance
Classification is performed for every 30 consecutive frames.