Canny算子子像素边缘检测方法

An Edge-detection Method of Sub-pixel Based on Canny Operator

在Canny算子的基础上,通过对梯度模值的内插求得沿边缘点梯度方向上相邻像素的梯度模值,利用这些梯度模值拟合二次曲线求出其极大值得到子像素定位的精确位置。通过推导,证明了梯度模在梯度方向上的极大值点就是边缘的精确位置。该算法在几乎没有增加计算量的前提下将Canny算子边缘检测精度提高到了子像素级。

This paper employs a quadratic interpolation of the values of the gradient norm by using three values in the gradient direction and then returns the position of the local maxima point as the exact position of the edge.The main advantage of this new method over other edge detectors is that it increases the edge detection accuracy to the level of sub-pixels while keeping the original amount of calculation.