find the coordinates 5 first white pixels in an image

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)

[Image Analyst]

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:

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[Rocío García Mojón]

Thank you very much.

I have an image like the first one and I would like to find the coordinates of the second photo, but with 4 additional points that are in the same column.

Answer 1

[Image Analyst]

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)

rowsInCol1 = 6×1

292 293 294 295 296 297

% Find all other pixels in the last column.
col2 = pix_amarelor(:, colum1last);
rowsInCol2 = find(col2)

rowsInCol2 = 6×1

714 715 716 717 718 719

[Rocío García Mojón]

Thank you very much!

[Dyuman Joshi]

Hello @Rocío García Mojón, if this answer solved your problem, please consider accepting the answer.

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[Rocío García Mojón]

Thank you @Dyuman Joshi