DTCWT denoising

So I poked at the wavelet code enough to get it to work, and included it in ImageZ. It still fails with certain sized images, but oh well ...

It's based on the dual-tree quaternion wavelet, and does a quaternion-to-complex translation during the thresholding which produces a cleaner de-noised result (i.e. it is still using a dual-tree-complex-wavelet-transform ...). I haven't particularly tried to optimise it much - but it's already about 3-4x faster than the DCT Denoising algorithm I implemented earlier (for which there is little opportunity for further improvement). It also implements the sharpen algorithm I developed, which I wasn't able to get to work with the DCT code.

I've started working on the OpenCL version for socles as well, but it's got a way to go yet.

The de-noising isn't my primary interest in this stuff, it's just a freebie to test some of the algorithms and is interesting nonetheless.

Update: Yes it's been a long time between drinks, but I finally poked at the socles GPU version again nearly 3 months later, see this follow-up post.