Top. Phantom and phantom noisy with 9%. Middle. The denoising result obtained with the optimized blockwise NLM with WM filter and the optimized blockwise NLM filter. Bottom. The image of difference between the phantom and the denoising result (i.e., -). The contrast of the zooms have been artificially increased. Visually, less structures have been removed with the optimized blockwise NLM with WM filter.
