Coordinates pixel (cpselect)

Hello,
Im using this cpselect function to select control points on two images. I can get those coordinates of each control point,which is great. The problem is that those coordinates aren't pixel coordinates. how can i get my pixel coordinates from an image using an interactive method?

 Accepted Answer

Amith Kamath
Amith Kamath on 30 Oct 2011
I would recommend using the function ginput instead, for example:
I = imread('rice.png');
imshow(I) %This is necessary for the ginput function expects a figure window to be open.
[x y] = ginput(n) %Where n is the number of points you need to interactively select.
and the x and y coordinates (of the pixel selected) will be stored in the vectors x and y.
Hope this helps!

3 Comments

Amith,
This is another approach for i want to do. It's the same coordinates using cpselect. But i've understood that those coordinates are all ready pixel coordinates.The problem was that in my college we dont consider an pixel coordinate an float number, so that's why i felt mistaken.
Thanks for your answer anyway, i didn't know ginput() function, it's great!
Best Regards,
Edward
Hello. In my case, I have an USB monochromo camera(only detects white and black) connected to the computer. The video will show a circle and 2 points. One does not move, and the other one does. I would like to get the coordinates from each point and then compare it. This information would be later processed, so I want to save the coordinates in vectores. Which functions would you recommend? Thank you
David, start a new question and attach your image with the circle and fixed point and other, second point, and the other image with the other, second point at a different location.

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