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

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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?

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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

Selva Karna
Selva Karna on 3 Aug 2017
Hi Swarooph , thanks for answer , actually my question is extract nearest pixel [ROI] its means region so , how to extract region by selection of pixel value?
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.

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