针对传统的Canny算子采用高斯滤波会造成图像的过度平滑并导致弱边缘检测能力降低的缺点，提出了一种改进的Canny边缘检测算法，采用中值滤波代替高斯滤波，利用中值滤波器能有效地清除脉冲噪声的优点以提高边缘检测精度。该算法在FPGA(现场可编程门阵列)上得以实现，实验结果表明改进后的算法提高了弱边缘的检测能力。

Aiming at the problem that the traditional Canny algorithm using Gaussian filter will cause excessive image smoothing and reduce the ability to detect the weak edge, an improved Canny algorithm using the median filter which can effectively remove impulse noise and improve the precision of edge detection to instead Gaussian filtering is represented. And this algorithm is realized in FPGA (Field Programmable Gate Array) and experimental results have showed that it can improve the ability to detect the weak edge.