Path detection in MATLAB

Question

I am trying to understand this code:

d=edge(d,'canny',.6);
figure,
imshow(d,[])

ds = bwareaopen(d,40);
figure,
imshow(ds,[])

iout = d1;
BW=ds;

iout(:,:,1) = iout;
iout(:,:,2) = iout(:,:,1);
iout(:,:,3) = iout(:,:,1);
iout(:,:,2) = min(iout(:,:,2) + BW, 1.0);
iout(:,:,3) = min(iout(:,:,3) + BW, 1.0);

I understand that dthis is an image, and the canny detector is applied, and 40 pixels are ignored. The image is a gray scale, and the outline is added to the image.

Could you explain the following lines? What principle / algorithm is used here? I'm having problems, especially with the code path definition part.

Answer 1

, d1 , , , ( 0 1) , , 5 RGB iout, , , .

'cameraman.tif', MATLAB :

d1 = double(imread('cameraman.tif'))./255;  % Load the image, scale from 0 to 1
subplot(2, 2, 1); imshow(d1); title('d1');  % Plot the original image
d = edge(d1, 'canny', .6);                  % Perform Canny edge detection
subplot(2, 2, 2); imshow(d); title('d');    % Plot the edges
ds = bwareaopen(d, 40);                     % Remove small edge objects
subplot(2, 2, 3); imshow(ds); title('ds');  % Plot the remaining edges
iout = d1;
BW = ds;
iout(:, :, 1) = iout;                           % Initialize red color plane
iout(:, :, 2) = iout(:, :, 1);                  % Initialize green color plane
iout(:, :, 3) = iout(:, :, 1);                  % Initialize blue color plane
iout(:, :, 2) = min(iout(:, :, 2) + BW, 1.0);   % Add edges to green color plane
iout(:, :, 3) = min(iout(:, :, 3) + BW, 1.0);   % Add edges to blue color plane
subplot(2, 2, 4); imshow(iout); title('iout');  % Plot the resulting image

, :

...

iout . , . 2-D , , , , : ( , ) RGB ( , ).

3 RGB, - ( , ). , , . BW (, ) , , , . min , , 1.0, , RGB .

, RGB :

iout = d1;
iout(:, :, 2) = min(d1+ds, 1.0);
iout(:, :, 3) = min(d1+ds, 1.0);