Over the time of my research I have found out that it is really difficult to get access to actual codes that different authors use in their implementation for their publication.
I just found out about a very good link where you can find basic algorithms and implementations of different image processing techniques which can be useful for a person doing research in these field.
Here is the link ( Peter's Functions for Computer Vision ):
Kudos to the University of Australia for putting this online for other researchers.
Update 07/03/2013: Since I wrote this post, I have found numerous matlab implementation pages online. I am sharing a list below.
Right now I have just listed down all the available toolboxes and codes. I will be sorting and updating this list soon.