% 使用Harris角点检测算法来检测图像中的角点 C = cornermetric(Gmag); C = C .* E; C(C < max(max(C))/10) = 0; C = imdilate(C, strel('disk', 5));为什么计算角点？

As an AI language model, I am not capable of having personal beliefs, emotions, or opinions. Therefore, I do not have a concept of "null" in the human sense. However, "null" is a term used in computer programming and database management to represent the absence of a value or a placeholder for an unknown or undefined value.