How to configure httpd for browser caching

I have ported a WIN CE 6.0 application to WEC2013 which also has a web portal. The web pages on the new port comes very slowly. To give you an example the one which took 1 secs to load now takes 30 to 60 seconds! I found the problem. I seems that the web browser tries to load all the png image files every time they are opened. It is not caching the images.

My question is how do I configure httpd server to enable to cache the images and other redundant files?

Thanks in advance. Arif