Find same points in two images?

Hello, I am trying to get same points in two different image, I have two picture the first is http://postimg.org/image/z2efq2p1b/fc9111a6/ and second is http://postimg.org/image/c6h55eis1/d7d69296/ and i want to select 3 white dot in that image based on intensity in first picture. And then i want to select the same 3 white dots in nest picture. I want to get their pixel values in both images. I am not sure how to do it. I read that I have to consider Gaussian function but I didn't understood. Any help with the code will be appreciated. Thanks