I need to count out boxes in a warehouse by using edge detection techniques, images will be taken from a 3D model of a warehouse and the propose system will be used 3 images in 3 different angles to cover the whole area of a warehouse. As I have no experience in image processing before I'm a bit confused about which algorithm to use.
For a quick start I would suggest looking at those two:
* Sobel operator
* Canny operator
These are the most widely used edge detection filters with pretty good results.
If you are starting to learn computer vision, you should also learn about typical operations in image processing and convolution.
The OpenCV library is a great library which implements many algorithms of computer vision, including the two operators mentioned above.
Take a look at Image Processing Library for C++ question. You can find several useful links there. The suggested libraries not only have algorithm description but also their implementations.
Take a look at my two edge detection tutorials - one is based on convolution, the other - just simple math. Oh, and you must love pixel shaders to read this :)
regards