基于梯度相位编组的树枝识别新算法

为了能够快速准确地计算出果树枝干的空间位置,提出了一种基于梯度相位编组的Hough变换树枝检测新算法。利用改进的平方梯度法计算边缘点的梯度相位角,找出梯度相位直方图中多个阈值大于T的峰值。然后将具有相近梯度相位角的边缘点归为一组。最后对每组中的边缘点采用改进的两点表决Hough变换算法找出对应的直线参数。利用梯度相位角进一步验证参数的正确性。研究结果表明,提出的梯度相位编组直线检测方法具有速度快、检测误差小和鲁棒性强的特点,能够快速准确地实现果树树枝的定位和检测,对部分被遮挡的树枝的识别效果也较好。

New Method for Branch Recognition Based on Gradient Phase Grouping

A new method of Hough transform based on gradients phase grouping for branches detection was proposed to locate the position of branches of fruit trees accurately and rapidly. After the gradient phase of edge points was calcu- lated by using the squared gradient method, the histogram of gradicnts's direction was calculated. From the histogram, several peak values were found by threshold T. Then edge points were grouped according to their gradent phases, and points in each group almost had the same gradient's direction. At last, an improved two-points Hough transform was applied to edge points in each group to calculate the parameters of lines, and the gradent's direction of every group was used to affirm the correctness of the parameters. The research results show that the proposed method has the merits of high speed, low error and strong robustness, can locate the branches of fruit trees accurately and fastly, and also can de- feet part covered branches satisfactorily.