Comprehensive Analysis on the Effects of Noise Estimation Strategies on Image Noise Artifact Suppression Performance

In this paper, the effects of employing different noise estimation strategies on the performance of noise artifact suppression techniques in achieving high image quality has been investigated. Most literature on the subject tends to use the true noise level of the noisy image when performing noise artifact suppression. However, this approach does not reflect how such techniques would be used in practical situations where the true noise level is unknown, which is common in most image and video processing applications. Therefore, in practical situations, the noise level must first be estimated before a noise artifact suppression technique can be applied using the estimated noise level. Through a comprehensive analysis of different noise estimation strategies using empirical testing on a variety of images with different characteristics, the MAD wavelet noise estimation technique was found to be the overall preferred noise estimation technique for all popular noise artifact suppression techniques investigated (BM3D, bilateral, Neigh Shrink, BLS-GSM and non-local means). Furthermore, the BM3D noise artifact suppression technique, combined with the MAD wavelet noise estimation technique, was found to offer the best performance in achieving high image quality in situations where the noise level is unknown and must be estimated. The outcome of this research is clear recommendations that can be used in practise when suppressing noise artifacts exhibited in digital imagery and video.