So I have splashed out into Python 3.4.3 and opencv 3.0.0. I held off on Python 3.5.0 for now. I was looking at cv2.filter2D(...) (why is opencv 3 still being called cv2) which broadly does what it should (for large kernels it does the convolution with the discrete Fourier transform).
Also I started using vim again, and discovered that it has tabs now! It is my favourite IDE again.
A page from an odd cookbook, filtered
arbitrarily by directionally maximising green channel contrast. It looks artistic. I have written so many pictureless words that any excuse for an image has to do.