Image 索引超过矩阵维数-Canny边缘检测
我使用以下代码行使用canny edge detector进行边缘检测:Image 索引超过矩阵维数-Canny边缘检测,image,matlab,image-processing,edge-detection,Image,Matlab,Image Processing,Edge Detection,我使用以下代码行使用canny edge detector进行边缘检测: I=imread('bradd.tif'); figure,imshow(I); IDtemp = im2double(I); [r c]=size(I); ID(r,c) = 0; IDx(r,c) = 0; IDfil(r,c) = 0; IDxx(r,c) = 0; IDy(r,c) = 0; IDyy(r,c) = 0;
I=imread('bradd.tif');
figure,imshow(I);
IDtemp = im2double(I);
[r c]=size(I);
ID(r,c) = 0;
IDx(r,c) = 0;
IDfil(r,c) = 0;
IDxx(r,c) = 0;
IDy(r,c) = 0;
IDyy(r,c) = 0;
mod(r,c) = 0;
for i= 1 : r+4
for j = 1:c+4
if(i<=2 || j<=2 || i>=r+3 || j>=c+3)
ID(i,j) = 0;
else
ID(i,j) = IDtemp(i-2,j-2);
end;
end
end
%figure,imshow(ID);
filter=[2 4 5 4 2;4 9 12 9 4;5 12 15 12 5;4 9 12 9 4;2 4 5 4 2];
for i=1:5
for j=1:5
filter(i,j)=filter(i,j)/159;
end
end
%figure,imshow(filter);
for v = 3 : r
for u = 3 : c
sum = 0;
for i = -2 : 2
for j = -2 : 2
sum = sum + (ID(u+i, v+j) * filter(i+3, j+3));
end
end
IDx(u,v) = sum;
end
end
%figure,imshow(IDx);
IDxtemp = IDx;
for i= 1 : r+2
for j = 1:c+2
if(i<=1 || j<=1 || i>=r || j>=c)
IDfil(i,j) = 0;
else
IDfil(i,j) = IDxtemp(i-1,j-1);
end;
end
end
%figure,imshow(IDfil);
Mx = [-1 0 1; -2 0 2; -1 0 1]; % Sobel Mask in X-Direction
My = [-1 -2 -1; 0 0 0; 1 2 1]; % Sobel Mask in Y-Direction
for u = 2:r
for v = 2:c
sum1 = 0;
for i=-1:1
for j=-1:1
sum1 = sum1 + IDfil(u + i, v + j)* Mx(i + 2,j + 2);
end
end
IDxx(u,v) = sum1;
end;
end
%figure,imshow(IDxx);
for u = 2:r
for v = 2:c
sum2 = 0;
for i=-1:1
for j=-1:1
sum2 = sum2 + IDfil(u + i, v + j)* My(i + 2,j + 2);
end
end
IDyy(u,v) = sum2;
end
end
%figure,imshow(IDyy);
for u = 1:r
for v = 1:c
mod(u,v) = sqrt(IDxx(u,v)^2 + IDyy(u,v)^2) ;
%mod(u,v) = sqrt(IDxx(u,v)^2 + IDyy(u,v)^2);
end
end
%figure,imshow(mod);
modtemp = mod;
for i= 1 : r+2
for j = 1:c+2
if(i<=1 || j<=1 || i>=r || j>=c)
mod(i,j) = 0;
else
mod(i,j) = modtemp(i-1,j-1);
end;
end
end
%figure,imshow(mod);
theta(u,v) = 0;
supimg(u,v) = 0;
ntheta(u,v) = 0;
for u = 2 : r
for v = 2 : c
theta(u,v) = atand(IDyy(u,v)/IDxx(u,v));
if ((theta(u,v) > 0 ) && (theta(u,v) < 22.5) || (theta(u,v) > 157.5) && (theta(u,v) < -157.5))
ntheta(u,v) = 0;
end
if ((theta(u,v) > 22.5) && (theta(u,v) < 67.5) || (theta(u,v) < -112.5) && (theta(u,v) > -157.5))
ntheta(u,v) = 45;
end
if ((theta(u,v) > 67.5 && theta(u,v) < 112.5) || (theta(u,v) < -67.5 && theta(u,v) > 112.5))
ntheta(u,v) = 90;
end
if ((theta(u,v) > 112.5 && theta(u,v) <= 157.5) || (theta(u,v) < -22.5 && theta(u,v) > -67.5))
ntheta(u,v) = 135;
end
if (ntheta(u,v) == 0)
if (mod(u, v) > mod(u, v-1) && mod(u, v) > mod(u, v+1))
supimg(u,v) = mod(u,v);
else supimg(u,v) = 0;
end
end
if (ntheta(u,v) == 45)
if (mod(u, v) > mod(u+1, v-1) && mod(u, v) > mod(u-1, v+1))
supimg(u,v) = mod(u,v);
else supimg(u,v) = 0;
end
end
if (ntheta(u,v) == 90)
if (mod(u, v) > mod(u-1, v) && mod(u, v) > mod(u+1, v))
supimg(u,v) = mod(u,v);
else supimg(u,v) = 0;
end
end
if (ntheta(u,v) == 135)
if (mod(u, v) > mod(u-1, v-1) && mod(u, v) > mod(u+1, v+1))
supimg(u,v) = mod(u,v);
else supimg(u,v) = 0;
end
end
end
end
%figure,imshow(ntheta);
th = 0.2;
tl = 0.1;
resimg(u,v)= 0;
for u = 2 : r-1
for v = 2 : c-1
if(supimg(u,v) > th)
resimg(u,v) = 1;
else
if(supimg(u,v) >= tl && supimg(u,v) <= th )
resimg(u,v) = 1;
else
if (supimg(u,v) < tl)
resimg(u,v) = 0;
end
end
end
if (supimg(u-1,v-1) > th || supimg(u,v-1) > th || supimg(u+1,v-1) > th || supimg(u+1,v) > th || supimg(u+1,v+1) > th || supimg(u,v+1) > th || supimg(u-1,v+1) > th || supimg(u-1,v) > th)
resimg(u,v) = 1;
else
resimg(u,v) = 0;
end
end
end
figure,imshow(supimg);
figure,imshow(resimg);
有人能帮我解决这个问题吗??
感谢并问候。您的循环范围顺序错误,导致错误。如果将循环范围修改为
for u = 3 : r
for v = 3 : c
sum = 0;
for i = -2 : 2
for j = -2 : 2
sum = sum + (ID(u+i, v+j) * filter(i+3, j+3));
end
end
IDx(u,v) = sum;
end
end
问题解决了
我的猜测是,该代码仅适用于c==r
的方形图像
请注意,您没有使用Matlab的矢量化功能,它允许您将第一步缩短为:
ID = [zeros(2,c+4) ; [zeros(r,2) IDtemp zeros(r,2)]; zeros(2,c+4)];
filter=[2 4 5 4 2;4 9 12 9 4;5 12 15 12 5;4 9 12 9 4;2 4 5 4 2];
filter=filter/159;
for u = 1 : r
for v = 1 : c
IDx(u,v) = sum(reshape(ID(u+[0:4], v+[0:4]).* filter,25,1));
end
end
最后一个循环也可以进一步折叠,但这可能会使可读性成为一个问题
(编辑)循环可以(例如)替换为
IDx = conv2(ID, filter,'same');
谢谢你,伙计。成功了。我怎么能把它折叠起来??你能建议。。I’我不熟悉Matlab。。我使用它才两天……)谢谢@TryHard,我有类似的问题,但现在它显示了三个连续的边缘检测图像,显示了[link](i.imgur.com/i2KRxUT.jpg?1)我是如何处理这个问题的,我的matlab代码是
IDx = conv2(ID, filter,'same');