如何裁剪图像中的顶部、左侧、底部和右侧边界?

密码

%%// Tolerance in percentage for the outliers/noise in the image because 
%%// of which the edges are not perfectly vertical or horizontal and 
%%// the ovalish blobs are not "round" enough
f=2;

%%// Read in your image
img = im2bw(imread('patt1.png'));

%%// Main processing
sum1 = sum(img,1);
box_startx = find(sum1>0.33*size(img,1),1);
box_stopx = size(img,2) - find(fliplr(sum1)>0.33*size(img,1),1) + 1;

sum2 = sum(img,2)'; %'
box_starty = find(sum2>0.33*size(img,2),1);
box_stopy = size(img,1) - find(fliplr(sum2)>0.33*size(img,2),1) + 1;

blob_leftx = find(sum1>(1-0.01*f)*max(sum1),1);
blob_rightx = size(img,2) - find(fliplr(sum1)>(1-0.01*f)*max(sum1),1) + 1;

blob_topy = find(sum2>(1-0.01*f)*max(sum2),1);
blob_bottomy = size(img,1) - find(fliplr(sum2)>(1-0.01*f)*max(sum2),1) + 1;

top1 = img(1:blob_topy,box_startx+1:box_stopx);
left1 = img(box_starty:box_stopy-1,1:blob_leftx);
bottom1 = img(blob_bottomy:end,box_startx:box_stopx);
right1 = img(box_starty:box_stopy,blob_rightx:end);

%// Debug
figure,
subplot(2,2,1);imshow(top1)
subplot(2,2,2);imshow(bottom1)
subplot(2,2,3);imshow(left1)
subplot(2,2,4);imshow(right1)

输出