The Dynamic Decision Switch for Multiple Pixel Connected Component Labeling Algorithm

Connected component labeling is an indispensable and one of most time consuming tasks of the applications in computer vision. Many labeling algorithms have been introduced, such as scan plus connection table, scan plus union-find, and contour tracing etc. They would rather use byte data than bit data to represent the binary pixel, which is either 1 or 0, due to the heavy cost of bitwise operations. This paper will propose a mechanism employing bit data to stand for the binary image pixels and labeling multiple pixels in one labeling process so that it can turn the weakness of bit data into the strength. According to the test results run in ARM926EJ-S, this new mechanism can double the speed of the scanning and analysis phases of an array based scan plus union-find algorithm. Besides, the much smaller binary image buffer needed by this mechanism is critical for the limited hardware-resource embedded devices, which are implemented in the field of computer vision gradually.