How to create lines and calculate their lenghts

I need to create lines in the filtered image bellow (already filtered image of a bubble seeping into a tube (cropped image)) in a similar way to the orange lines (drawn randomly as an example using the software paint) already in the example figure (10 lines is fine) so that I can calculate the lengths of these lines and then make an average. Any idea how i could do this?

Thanks in advance!

cropped

filtered

example

clc; 
clear
close all;    

load('cropped.mat');
cropped = cortada;
figure, imshow(cropped);

gray = rgb2gray(cropped);
figure, imshow(gray);

thresh = im2bw(gray, 0.7);
figure, imshow(thresh);

remove = bwareaopen(thresh,13200);
figure, imshow(remove);

se = strel('line',400,0);
closingOperation = imclose(remove,se);
figure, imshow(closingOperation);

OriginalLine = closingOperation(1 , :);
OriginalLine2 = closingOperation(end , :);
closingOperation(1, :) = true;
closingOperation(end, :) = true;
filtered = imfill(closingOperation, 'holes');
closingOperation(end,:) = false;
closingOperation(1,:) = false;
filtered(1, :) = OriginalLine;
filtered(end, :) = OriginalLine2;
figure, imshow(filtered);

[Rik]

If your question is simply how to measure the length of those orange lines:

I would suggest using sum (or any) to determine which rows have white pixels, after which you can use find with the 'first' and 'last' options to find the start and end of the white area. You can use it on all, or a selection of rows.

[Jórdan Venâncio Leite]

Thanks for your answer Rik! I will try it.

[Jórdan Venâncio Leite]

Hi Rik! Put your answer bellow so i can choose as the best answer!!

[Jórdan Venâncio Leite]

It worked!!

Answer 1

[Image Analyst]

Jordan:

Why not do it for ALL widths (every single line of the blob), rather than just 10? Just simply do

verticalProfile = sum(binaryImage, 2); % A list of all possible widths - hundreds of them.
meanWidth = mean(verticalProfile);

If you really want exactly 10 lines dividing the blob into 11 sections, do this (untested):

[r, c] = find(binaryImage);
topRow = min(r)
bottomRow = max(r)
rows = linspace(bottomRow, topRow, 12); % 12 if you include the top row and bottom row.
% Don't include  very top or very bottom
rows = rows(2:end-1) % Only 10 now.
for k = 1 : length(rows)
    row = rows(k);
    col1 = find(binaryImage(row, :), 1, 'first');
    col2 = find(binaryImage(row, :), 1, 'last');
    width(k) = col2 - col1; % Add 1 if you want, depends on your definition of width.
end

[Jórdan Venâncio Leite]

Thanks for your answer Image analyst!

[Jórdan Venâncio Leite]

I will try It.

[Image Analyst]

Did it work?

[Jórdan Venâncio Leite]

I didnt try it yet

[Image Analyst]

But you actually did because Rik said to use sum() and find() but didn't give any code, and you said it worked. I also said that and additionally gave code for how to find the location of the "orange lines". So if you coded up Rik's suggestion, you actually did something like what I gave above.

[Rik]

And that is the reason why I didn't post my suggestion as an answer, as this answer gives a specific example of how to implement my suggestion.