The Optimized Algorithm of the Connected Area Based on FPGA

This paper proposes a connected area algorithm for processing a line of pixels collected by linearity CCD camera at a time based on FPGA. It can be used in material sorting equipment to separate materials of different sizes. The method is based on the twice scan method of the connected area, and implemented on FPGA, called two-row scan method. It needs to save only two rows of pixels and it is only one pixel in every scan unit. Because of scanning two rows of pixels every time, the real-time performance is extremely excellent. After calculating the area of the connected area, it will be selected and removed according to the upper limit and the lower limit while the location of the material is determined by the channel division algorithm and the high speed air valve. The area error calculated by this method is less than 5%, and the material elimination rate can reach more than 90%.