susan算法是基于灰度的特征点获取算法，适用于边缘提取。

function image_out=susan(image,threshold) mask=([0 0 1 1 1 0 0;0 1 1 1 1 1 0;1 1 1 1 1 1 1;1 1 1 1 1 1 1;1 1 1 1 1 1 1;0 1 1 1 1 1 0;0 0 1 1 1 0 0]); R=zeros(size(image)); nmax=3*37/4; [a b]=size(image); new=zeros(a+7,b+7); [c d]=size(new); new(4:c-4,4:d-4)=image; for i=4:c-4 for j=4:d-4 current_image=new(i-3:i+3,j-3:j+3); current_masked_image=mask.*current_image; current_thresholded=susan_threshold(current_masked_image,threshold); g=sum(current_thresholded(:)); if nmax<g R(i,j)=g-nmax; else R(i,j)=0; end end end image_out=R(4:c-4,4:d-4);