writing a gaussian blur filter

i'm trying to write a program that applies the filter effect gaussian blur to an imported bitmap in turbo c++ ide. not sure about how to go about doing this, but ive found several complicated algorithms related to this topic. (not sure how to implement those either) i've been informed that there are certain libraries that can be used to make life easier while writing such a program, and I was wondering if anyone knew what it was?

the libraries will depend on the compiler and os, but the concept of a gaussian blur is pretty simple to understand and implement. what specific parts are you having trouble with?

http://www.students.miami.edu/~rhartma1/gaus.cpp that's basically what i'm trying to do... but im not sure what the ascii and greypix does.

and there's also this error for int pic[256][171] something about the array being too large.