Benchmark for Abell 1689 image from Fig. 8 comparing CDL to DL and wavelet denoising methods: a) a centered learned dictionary that was learned on a second, noiseless image and used for denoising; b) the peak S/N curve for the three methods. Centered dictionary learning method is represented by the green curve, the classic dictionary learning in blue and the wavelet-based method in red. The horizontal axis represents the peak S/N (dB) between the image before and after adding noise. For denoising, we use OMP with a stopping criterion fixed depending on the level of noise that was added. 100 experiments were repeated for each value of noise.