MATLAB Answers

How to extract nearest pixel value [roi] by selection of reference pixel on a image?

5 views (last 30 days)
Selva Karna
Selva Karna on 2 Aug 2017
Commented: Binu on 3 Aug 2017
How to extract nearest pixel value [roi] by selection of reference pixel on a image?

Answers (1)

Swarooph
Swarooph on 2 Aug 2017
Use the impoint function.
Example:
img = imread('peppers.png');
figure;imshow(img)
h = impoint(gca,[]);
position = wait(h); %Double click on a pixel in the figure window
pixelLoc = round(position) %Get nearest pixel location
img(pixelLoc(2),pixelLoc(1),1:3) %Use pixel location to index into RGB image
Result:
pixelVal =
(:,:,1) =
158
(:,:,2) =
50
(:,:,3) =
56
  2 Comments
Binu
Binu on 3 Aug 2017
Swarooph's answer gives you both the pixel position(x,y) and pixel value. If you are looking for a ROI and not just a pixel, try imrect or imellipse. They both use the imroi class and functions are similar to impoint.

Sign in to comment.

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!