亚像元边缘检测系统的FPGA实现

提出了一种集成于单片FPGA的数字化线阵CCD边缘检测系统。通过对CCD输出图像的边缘灰度梯度分析,利用高斯滤波除噪、边缘检测算法确定其像元级边界,并提出了一种以最小二乘多项式拟合来确定亚像元级边界位置的新算法。整个系统以现场可编程门阵列器件作为核心及数字电路硬件的载体,利用VHDL语言及图形化输入方式在QuartusⅡ7.2软件平台上进行了系统的设计。误差分析及仿真结果表明,该边缘检测系统的分辨率可达到将近六十分之一的像元宽度,可应用于研制高精度CCD光电自准直仪。

Realization of Measuring the Sub-pixel Edge System Based on FPGA

A new digital system of edge detecting based on a single FPGA was designed in this paper. By analyzing the signal of CCD output and the grads of grey scale breaks at the edge of picture the pixel edge of picture, the gauss filter was used to remove the noise, the pixel edge of picture was detected by the edge algorithm which can be used to detect the edge of picture automatically, and the least-squares polynomial fitting algorithm was used to detect the sub-pixel edge of picture. FPGA device was used as the core of the system and the carrier of digital circuit. The system was designed with VHDL and image input in Quartus ii7.2 software. It was proved to have the resolution of nearly 1/60 pixel width and can be used in the application of developing the photoelectrical autocollimation.