基于小波变换的小尺度边缘检测的matlab实现（毕设专用）

Img = imread('Lena.jpg'); figure,imshow(Img),title('原始图像'); if ndims(Img) == 3 img = rgb2gray(Img); %灰度图像 end X = img; x=X; x=double(x); [line,column,dim]=size(x);%获取图像尺寸 Tu=7; smooth_area_num=20; edge_area_num=20; for J=6:2:10 %显示多尺度小波变换边缘检测 %获取每一行的小波分解系数 for i=1:line coef1(i,:)=cwt(x(i,:),1,'bior4.4'); coef2(i,:)=cwt(x(i,:),2,'bior4.4'); coef3(i,:)=cwt(x(i,:),J,'bior4.4'); end max=0; max_loc=0; max_num=15; for i=1:line j=1; while j<column-1 %寻找小波系数中的极大值和极小值 if (coef3(i,j)>0 && coef3(i,j+1)<0) || (coef3(i,j)<0 && coef3(i,j+1)>0 )%找到左位置j for k=j+1:column-1 if coef3(i,k)*coef3(i,j)>=0%找到右位置k for m=j:k if abs(coef3(i,m))>max max=abs(coef3(i,m)); max_loc=m; end end if max>max_num form(i,max_loc)=1; end j=k; max=0; break; end end if k==column-1 j=column-1; end else j=j+1; end end end %对列作小波变换 x=x'; for i=1:line coef1(i,:)=cwt(x(i,:),1,'bior4.4'); coef2(i,:)=cwt(x(i,:),2,'bior4.4'); coef3(i,:)=cwt(x(i,:),J,'bior4.4'); end %正值1，负值0的矩阵temp表示(突变点左位置） max=0; max_loc=0; for i=1:line j=1; while j<column-1 %寻找小波系数中的极大值和极小值,同上 if (coef3(i,j)>0 && coef3(i,j+1)<0) || (coef3(i,j)<0 && coef3(i,j+1)>0 )%找到左位置j for k=j+1:column-1 if coef3(i,k)*coef3(i,j)>=0%找到右位置k for m=j:k if abs(coef3(i,m))>max max=abs(coef3(i,m)); max_loc=m; end end if max>max_num form(max_loc,i)=1; end j=k; max=0; break; end end if k==column-1 j=column-1; end else j=j+1; end end end %%边缘点的判断 for i=2:line-2 for j=2:column-2 %链长为1 if form(i,j-1)==0 & form(i,j+1)==0 & form(i-1,j-1)==0 & form(i-1,j)==0 & form(i-1,j+1)==0 & form(i+1,j-1)==0 & form(i+1,j)==0 & form(i+1,j+1)==0 form(i,j)=0;% end if form(i,j)==1 & form(i,j+1)==1 & sum(sum(form(i-1:i+1,j-1:j+2)))==2 form(i,j)=0; form(i,j+1)=0; end if form(i,j)==1 & form(i+1,j)==1 & sum(sum(form(i-1:i+2,j-1:j+1)))==2 form(i,j)=0; form(i+1,j)=0; end if form(i,j)==1 & form(i+1,j+1)==1 & sum(sum(form(i:i+1,j:j+1)))==2 if sum(sum(form(i-1:i+2,j-1:j+2)))==3 & ( form(i-1,j+2)==1 | form(i+2,j-1)==1) form(i,j)=0; form(i+1,j+1)=0; end if sum(sum(form(i-1:i+2,j-1:j+2)))==4 & form(i-1,j+2)==1 & form(i+2,j-1)==1 form(i,j)=0; form(i+1,j+1)=0; end end if form(i,j+1)==1 & form(i+1,j)==1 & sum(sum(form(i:i+1,j:j+1)))==2 if sum(sum(form(i-1:i+2,j-1:j+2)))==3 & ( form(i-1,j-1)==1 | form(i+2,j+2)==1) form(i,j+1)=0; form(i+1,j)=0; end if sum(sum(form(i-1:i+2,j-1:j+2)))==4 & form(i-1,j-1)==1 & form(i+2,j+2)==1 form(i,j+1)=0; form(i+1,j)=0; end end end end max=0; %%确定最终的边缘图 for i=3:line-3 for j=3:column-3 s=sum(sum(form(i-2:i+2,j-2:j+2))); for m=i-2:i+2 for n=j-2:j+2 if s>=7 && abs(coef3(m,n))<=s*3 form(m,n)=0; end end end end end figure(J), imshow(form, []);title('基于小波变换多尺度的边缘检测图'); end