Crop an image using coordinate

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hu
hu on 2 Oct 2014
Commented: Image Analyst on 16 May 2022
Hi,
How can I crop an image by having the top left coordinate (X1,Y1) and bottom right (X2,Y2).
I2 = imcrop(im,[x1 y1 x2 y2])
does not seem to work?
Thanks
  3 Comments
Image Analyst
Image Analyst on 14 Jan 2020
Nisa, start a new question, and give the code that you used to load up your images structure (was it the dir function?). Your images structure is evidently empty, meaning it found not images.
filePattern = fullfile(pwd, '*.png');
images = dir(filePattern);
if isempty(images)
message = sprintf('No PNG images found in folder %s\n', pwd)
uiwait(errordlg(message))
return;
end
thisImage=imread(images(1).name);
imshow(thisImage)
% Crop one to get rect
croppedImage = imcrop(thisImage);

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Accepted Answer

Image Analyst
Image Analyst on 2 Oct 2014
You used 151 instead of 115 in your width. Here, try this:
grayImage = imread('circuit.tif');
subplot(1,2,1);
imshow(grayImage);
h = impixelinfo();
axis on;
I2 = imcrop(grayImage,[115, 89, 161-115,142-89]);
subplot(1,2,2);
imshow(I2)
axis on;
  2 Comments
Image Analyst
Image Analyst on 16 May 2022
I don't know. It looks like the original poster changed/edited his post. It no longer mentions 151 and he removed the image.

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More Answers (3)

John BG
John BG on 4 Mar 2017
Edited: John BG on 4 Mar 2017
Hi Hu
A=imread('im1.jpg');imshow(A)
p=ginput(2)
p1max=max(p(:,1));p2max=max(p(:,2));p1min=min(p(:,1));p2min=min(p(:,2));
A(:,[1:p1min],:)=[];
A([1:p2min],:,:)=[];
A(:,[uint64(p1max-p1min+1):end],:)=[];
A([uint64(p2max-p2min+1):end],:,:)=[];
imshow(A)
EXPLANATION
1.
as example let's start with this image
A=imread('im1.jpg');imshow(A)
2. Selecting 2 diagonal points that define the borders you want to remove. I use command ginput but you already have the values
p=ginput(2)
3. Calculating border values from ginput points
p1max=max(p(:,1));p2max=max(p(:,2));p1min=min(p(:,1));p2min=min(p(:,2));
4. Removing on borders, one side of the frame at a time
A(:,[1:p1min],:)=[];
A([1:p2min],:,:)=[];
A(:,[uint64(p1max-p1min+1):end],:)=[];
A([uint64(p2max-p2min+1):end],:,:)=[];
5.
Check
imshow(A)
Hu
if you find these lines useful would you please mark my answer as Accepted Answer?
To any other reader, if you find this answer of any help please click on the thumbs-up vote link,
thanks in advance for time and attention
John BG

Nalini Vishnoi
Nalini Vishnoi on 2 Oct 2014
You can try using the following command
I2 = imcrop(im,[x1 y1 x2-x1 y2-y1]);
imcrop uses the following syntax:
I2 = imcrop(I,RECT);
where RECT is a 4-element vector with the form [XMIN YMIN WIDTH HEIGHT];
  3 Comments
hu
hu on 2 Oct 2014
Edited: hu on 2 Oct 2014
Hi,
If I wish to crop the image (get the square in the middle) and based on the code sugested, It does not work:
I=imread('circuit.tif');
I2 = imcrop(I,[115, 89, 161-151,142-89]);
imshow(I2)
The coordiantes are (115,89,161,142) (Xtop left,Ytop left, Xbottom right, Ybottom right).
Thanks

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Amruta Talreja
Amruta Talreja on 4 Mar 2017
I2 = imcrop(B1,[12659 11677 11281 12661]); imshow(I2); I wrote this code and i am getting a blank screen. plz help.
  4 Comments
Image Analyst
Image Analyst on 13 Jul 2019
If you use imcrop() without any arguments, you'll be in interactive drawing mode.

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