find pixels of a line in picture

Hello everyone, i have a question maybe its really easy but i dont really know how to do it.

How can i find the pixels in the pixture that corresponde in a certain line within the picture.

For example if i have the image bellow and i draw the red line as shown below how can i find the pixels of the image that are in that line.

Answer 1

[KALYAN ACHARJYA]

% Load the image
rgbImage=imread('image_line.png');
% Get the one plane/Gray Image
red_channel=rgbImage(:,:,1);
% Segment the ROI 
line_seg=bwareafilt(imbinarize(red_channel,0.85),1);
% Display the Region of Interest
figure,imshow(line_seg);
% Get the rows and column indices of ROI
[r,c]=find(line_seg==1);
% Get the pixel values of particular rows & columns
rgbImage(r,c,:)

Note: you may get 3 pixels values for single row & cloumns indices, as there are three plane in the RGB image.

[lena kappa]

thanks for the answer

i get only a white cyrcle when i run your code my picture is not rgb its grayscale

does this code work for grayscale and binary pictures also

[KALYAN ACHARJYA]

The original attached image is RGB image

[lena kappa]

yes you are right it was my mistake.

what i wanted was to first draw the line in the pic and then find the coresponding pixel.

So for example if i want to draw a line 45 degrees starting from the point (0,0) of the pic and then find the coresponding pixels of that line.

Sorry if i did not post my question very crearly.