Abstract: The edge detection is one of the fundamental topics in the image analyses and the computer vision.Firstly the traditional operator methods are introduced.Secondly two methods，which arisen in recent years，of multi-scale edge detection based on wavelet transform and mathematical morphology are introduced.Furthermore the algorithms and performances are also described.Finally by using those images after edge detection based on the above technologies，the area of a reservoir are calculated，and the results are compared and analyzed.The result proves that the accuracy of the multi-scale edge detection based on wavelet and mathematical morphology are higher than all traditional operator methods.

摘要： 图像边缘是一种重要的视觉信息，是图像最基本的特征之一。首先介绍了经典的边缘检测算子，然后进一步介绍了近年来出现的基于小波变换的多尺度边缘检测以及数学形态学的边缘检测方法，对其性能和算法特点进行了分析，最后将所有的边缘检测方法应用于水库面积计算中，同时对结果数据进行了比较分析。结果证明，基于小波变换的多尺度边缘检测以及数学形态学的边缘检测得出的水库面积精度高于其他算子。