Parallel programming and Image processing

I'm looking for one of Image processing algorithms implementing base on gpu parallel programming and to see the performances when is operating with CPU (as series computing) and same same algorithm of Image processing operate as GPU (parallel computing) and finally see the comparative for both how much fast. Image processing algorithm like: BLOB or Connected component labeling.

I saw Steve blog actually he published too many benefit files with good explain including connected component but as a series programming on cpu only, however briefly for example I want see connected component labeling codes for both cases first running on CPU with calculating computational time and second with GPU as well.

to identify the differences how many times GPU CUDA are faster than CPU.

[Matt J]

It's hard to imagine how you could parallelize component labeling, whether on the CPU or GPU. It seems like an inherently non-parallel operation.