hi,dear fva,in my previous question about how to compare the two id pictures to decide whether they are the same person or not,you answered me with these information:
"I agree, it's a complicated issue. On a simplified environment (same background, roughly same face size,
something like person pictures on ID cards) you can try something like this:
1. equalize the contrast and the brightness of the images
2. break the images in small squares. How small - you should experiment
3. Compare then the corresponding squares. If you have color info in the images, go for color comparision
first, then for the luminance component.
4. Offer a decision based on some treshold. Which one - you should experiment."
Now,here is my question:1.why should we equalize the contrast and the brithtness of the images firstly?Could you tell me?
2.why should we break the images in small squares?Any convincible reasons for it?
Hope to hear from you soon.Thank you.