Noise Reduction with Non-Local Mean and Hierarchical Edge Analysis

Noise reduction is a very important step in digital image processing. The noise problem is serious in cell phone and video camera. The noises result in lower image quality. Moreover, users can not take a satisfactory photo. Furthermore, other digital image processing may also increase the noises. For example, digital image stabilization by raising the ISO speed will increase the noise level.n this thesis, we use non-local means and hierarchical edge analysis to reduce noises. Our method not only preserves the detail of the edge area with non-local means but also retains noise reduction on non-edge area with hierarchical edge analysis.