find the coordinates 5 first white pixels in an image
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Rocío García Mojón
on 30 Aug 2023
Commented: Rocío García Mojón
on 4 Sep 2023
I am trying to find the coordinates of the first 5 white pixels of a black and white image. With the find function I am able to find the first and the last one, but I need more, could someone help me? Thanks
%Find coordinates of the last and first white pixel
%First image
pix_amarelor = imread('pac14_e.png')
[row1first,colum1first] = find(pix_amarelor,1,'first');
imshow(pix_amarelor);
hold on;
plot(colum1first,row1first,'r+','LineWidth',2,'MarkerSize',30);
[row1last,colum1last] = find(pix_amarelor,1,'last');
% imshow(pix_amarillor);
hold on;
plot(colum1last,row1last,'r+','LineWidth',2,'MarkerSize',30)
2 Comments
Image Analyst
on 30 Aug 2023
Depends on how you define "first". Attach 'pac14.png' and tell us what pixels you consider to be the "first". And format your code as code with the code icon/button.
If you have any more questions, then attach your data and code to read it in with the paperclip icon after you read this:
Accepted Answer
Image Analyst
on 31 Aug 2023
Try this:
% Find coordinates of the last and first white pixel
% First image
pix_amarelor = imread('pac14_e.png');
[row1first,colum1first] = find(pix_amarelor,1,'first');
imshow(pix_amarelor);
hold on;
plot(colum1first,row1first,'r+','LineWidth',2,'MarkerSize',30);
[row1last,colum1last] = find(pix_amarelor,1,'last');
% imshow(pix_amarillor);
hold on;
plot(colum1last,row1last,'r+','LineWidth',2,'MarkerSize',30)
% Find all other pixels in the first column.
col1 = pix_amarelor(:, colum1first);
rowsInCol1 = find(col1)
% Find all other pixels in the last column.
col2 = pix_amarelor(:, colum1last);
rowsInCol2 = find(col2)
3 Comments
Dyuman Joshi
on 1 Sep 2023
Hello @Rocío García Mojón, if this answer solved your problem, please consider accepting the answer.
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