opencl sobel filter and theory

i would implement and modify(for my application)the sobel filter in opencl(i saw the example in the nvidia opencl sdk and works fine), but first i would understand the theory of the sobel filter .
where i can read about the theory?in books or google?


Take a look at the Sobel Filter for some accessible background info, and at Image Convolution for more details about optimizing the kernel in OpenCL.


I’m start reading, i have a doubt:
for understand better the sobel filter:
The matrix system is a method for gain-time for find the edges?
isn’t possible to test pixel for pixel the difference of color of neighbors pixels and see if it’s in a range and if it is select the pixel?

it’s only a compute method?