applying a blur filter to a .bmp image

[axtyax]

As the title suggests, I would like to apply a simple blur filter to my .bmp image, but without using any sort of built in tools.

All I really need is for someone to show me the mathematics of the blur filter, and how I would go about implementing it into a c++ program. (keep in mind, I am programming in Linux, so I cant use many functions that you can in Windows programming.)

Thanks in advance!

[z05DSL3A]

Read up on Image convolution and Gaussian blur