Recording devices whether analog or digital, have traits which make them susceptible to noise. In selecting a noise reduction algorithm, one must weigh several factors. Image denoising is defined as a method to recover a true image from an observed noisy image and is applied in display systems to improve the quality of image. One of the popular denoising methods, NLM, produces the quality of im...

Visual information transmitted in the form of digital images is becoming a major method of communication in the modern age. All digital images contain some degree of noise. Removing noise from the original signal is still a challenging problem for researchers. In this paper, the non-local denoising approach presented by Buades et al. is compared and analyzed by Fast nonlocal means algorithm. Th...

This paper describes a novel theoretical characterization of the performance of non-local means (NLM) for noise removal. NLM has proven effective in a variety of empirical studies, but little is understood fundamentally about how it performs relative to classical methods based on wavelets or how its parameters should be chosen. For cartoon images and images which may contain thin features and r...

A new local search heuristic, called J-Means, is proposed for solving the minimum sum-of-squares clustering problem. The neighborhood of the current solution is deened by all possible centroid-to-entity relocations followed by corresponding changes of assignments. Moves are made in such neighborhoods until a local optimum is reached. The new heuristic is compared with two other well-known local...

High-Angle Annular Darkfield Scanning Transmission Electron Microscopy (HAADF-STEM) allows to take images at atomic scale with a contrast proportional to the atomic number. STEM acquires an image line-by-line, pixel-by-pixel leading to characteristic distortions. Furthermore, STEM images of beam sensitive materials have to be taken with short exposure times, leading to low contrast images with ...

Non-local means (NLM) is a popular image denoising scheme for reducing additive Gaussian noise. It uses a patch-based approach to find similar regions within a search neighborhood and estimates the denoised pixel based on the weighted average of all pixels in the neighborhood. All weights are considered for averaging, irrespective of the value of the weights. This paper proposes an improved var...

Non-local means (NLM) is a popular image denoising scheme for reducing additive Gaussian noise. It uses a patch-based approach to find similar regions within a search neighborhood and estimate the denoised pixel based on the weighted average of all the pixels in the neighborhood. All the pixels are considered for averaging, irrespective of the value of their weights. This thesis proposes an imp...