I just released a pytorch implementation of the HDMI denoising method that can be used on GPU: github.com/ahoudard/HDMI

This version allows to run the EM algorithm and the denoising in about half a minute!

python run_HDMI_denoising.py alley.png --stdv 0.1 --n_iter 40 --verbose --gpu
selected device: cuda
run EM algorithm...
denoise patches...
total runtime: 34s
PSNR: 29.8940dB