How to use ginput to determine the coordinates of an image

I have a matrix of 4 images (2x2) and I want to use ginput to select an image and with that selection, determine which image it is. For example, if I click on (3000,2000) I want the program to tell me it is the orange flower image.

Answer 1

[KSSV]

You have dimensions of each image...say dimensions of each image [m,n,3]. Initiate a matrix idx such that, each quarter has the value 1, 2, 3, 4 for each respective image. When you get [x,y] use interp2, and get the value.

idx = zeros(2*m,2*n) ; 
idx(1:m,1:n) = 1 ;   % first image 
idx(1:m,n+1:end) = 2 ; % second image 
idx(m+1:end,1:n) = 3 ; % third image 
idx(m+1:end,n+1:end) = 4 ; % fourth image 

p = interp2(idx,3000,2000)    % see the value and decide the image