DCT (discrete cosine transform) Calculation for image processing (blur detection)

This is a sample project with functions that

1. Create a matrix from an image (each value represents the luminance of that pixel)
2. Calculates a DCT matrix from an image matrix
3. Calculates an inverse DCT matrix (for testing purposes)

This is a starting point for image processing in Swift.

Inspired by the accepted answer here: http://stackoverflow.com/questions/8310749/discrete-cosine-transform-dct-implementation-c/8311564#8311564

More info on DCT: https://en.wikipedia.org/wiki/Discrete_cosine_transform