How to get the value from Structure array ?
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Dear Matlab experts,
I need some help from someone.
I want to get the location value from the structure array (stat). Then use them to crop image with the size is 64x64.
This is my step:
- Detect the centroid of image
2. Use the value of centroid location and crop the original to many 64x64 image.( this step i stuck because i don't know how to get the
value of centroid location).
My code:
% Step 1 centroid detection
I=imread("2_mask.png")
Ibw = im2bw(I);
stat = regionprops(Ibw,'centroid');
imshow(I); hold on;
for x = 1: numel(stat)
plot(stat(x).Centroid(1),stat(x).Centroid(2),'+',LineWidth=2);
end
hold off
%Step 2 crop image
I2 = imcrop(I,[??-32 ??-32 63 63])
This is the structure array value of centroid location.
This is what i want to do
Thanks
Han
采纳的回答
I=imread("https://www.mathworks.com/matlabcentral/answers/uploaded_files/996660/2_mask.png");
Ibw = im2bw(I);
stat = regionprops(Ibw,'Image');
for i=1:numel(stat)
I=stat(i).Image;
I(end+1:64,end+1:64)=0;
s=regionprops(I,'Centroid');
I=imtranslate(I,32-s.Centroid);
if ~isequal(size(I),[64,64])
win = centerCropWindow2d(size(I),[64,64]);
I=imcrop(I,win);
end
stat(i).Image=I;
end
montage({stat.Image},'Back','w','Bor',5)
1 个评论
Jenifer NG
2022-5-13
编辑：Jenifer NG
2022-5-13
Thanks you so much.
I want to use the centroid location in this image to crop another image then save the cropped area to separate file.
Could you help me to modify this code?
更多回答（1 个）
I want to use the centroid location in this image to crop another image then save the cropped area to separate file.
I=imread("https://www.mathworks.com/matlabcentral/answers/uploaded_files/996660/2_mask.png");
Ibw = im2bw(I);
stat = regionprops(Ibw,'Centroid');
N=numel(stat);
for i=1:N
stat(i).BoundingBox=[stat(i).Centroid-32.5, 64,64];
end
And now you can extract the cropped subimages from an arbitrary image with the following, although I use the original image Ibw just for illustration.
subimages=arrayfun(@(s)imcrop(Ibw,s.BoundingBox), stat,'uni',0); %You can use a new image here
montage(subimages,'Back','w','Bor',5)
5 个评论
Jenifer NG
2022-5-13
编辑：Jenifer NG
2022-5-13
Why not save them all to the same file, as follows?
save myFile subimages
Jenifer NG
2022-5-13
编辑：Jenifer NG
2022-5-13
Jenifer NG
2022-5-13
编辑：Jenifer NG
2022-5-13
Dear Matt J,
I am using the function to convert subimage from array to mat (array2mat) then i can save the cropped image by using imwrite and the code as bellow . Could you advise me to modify the code ?
clear all
I=imread("https://www.mathworks.com/matlabcentral/answers/uploaded_files/996660/2_mask.png");
Ibw = im2bw(I);
stat = regionprops(Ibw,'Centroid');
N=numel(stat);
for i=1:N
stat(i).BoundingBox=[stat(i).Centroid-32.5, 63,63];
end
I2=imread("2.png")
subimages=arrayfun(@(s)imcrop(I2,s.BoundingBox), stat,'uni',0); %You can use a new image here
montage(subimages,'Back','w','Bor',5)
for k = 1:N
b{k}=cell2mat(subimages(k,1))
filename=sprintf('file%d.jpg',k)
imwrite(b{k},filename)
end
Thanks
Matt J
2022-5-13
Why is modification necessary?
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