一种改进的桥梁图像分水岭分割算法

针对传统分水岭分割方法存在的过分割问题,提出了一种改进的桥梁图像分水岭分割算法。该算法首先对桥梁裂缝图像进行高低帽形态学滤波,并运用多尺度梯度算子提取梯度图像,在分水岭变换之前使用自适应的标记提取方法对区域极小值进行标定,然后对初步分水岭分割的过分割区域使用改进fisher距离的区域合并算法进行合并,取散度作为停止度量。实验表明,该算法减少了分水岭算法的过分割现象,提高了桥梁图像分割的精确性,具有很好的鲁棒性和适应性。

An improved watershed segmentation algorithm for bridge image

In order to solve the over-segmentation problem of the traditional watershed algorithms，an improved watershed segmentation algorithm for the bridge image is proposed. Firstly，input images are filtered by top-hat transformation and bottom-hat transformation. Secondly, a multi-scale algorithm for computing morphological gradient images is proposed, and the threshold for marker-extraction is automatically calculated according to the statistics of local extreme points in the gradient map. Thirdly, the watershed algorithm is applied to the modified gradient map to segment the image, and the over-segmentation regions of the initial watershed segmentation is settled by region merging based on fisher distance, which is ended according to divergence principle．Experimental results show that over segmentation phenomenon can be reduced significantly, and the image accuracy is improved while maintaining strong robustness and adaptability．