How to reduce the processing time for image registration

Hi, I did intensity based image registration with visible image of 1280x720 and thermal image with 240x320 resolution. It took 42seconds to run on my machine. Why is matlab very slow, how do i decrease the processing time? My project is about detecting elevated body temperature, so I need a very quick image registration. Can you please give your suggestion about how to reduce the processing time, other techniques available , or do I have to shift to any other programming language that is faster?