High precision edge detecting algorithm and realization of linear CCD based on FPGA

In order to improve the precision and speed of the linear CCD edge detecting system, in this paper, we proposed a new digital system which was used to detect the sub-pixel edge of the picture based on FPGA. Firstly, the CCD signal had been filtered by average filter before it entered the edge detecting system; secondly, the pixel edge can be detected by the algorithm that was used to detect the edge of the picture automatically, because the grads of grey scale breaks at the edge of the picture; lastly, cubic polynomials algorithm was used to detect the sub-pixel edge of picture. The edge detecting algorithm based on FPGA was designed with VHDL and Quartus II software, and the precision of the edge detecting algorithm was simulated and testes by using of MATLAB. The simulation and test results proved that the edge detecting algorithm in this paper had the characteristic of high precision, speed, and integration.