4,465 research outputs found
High-ISO long-exposure image denoising based on quantitative blob characterization
Blob detection and image denoising are fundamental, sometimes related tasks in computer vision. In this paper, we present a computational method to quantitatively measure blob characteristics using normalized unilateral second-order Gaussian kernels. This method suppresses non-blob structures while yielding a quantitative measurement of the position, prominence and scale of blobs, which can facilitate the tasks of blob reconstruction and blob reduction. Subsequently, we propose a denoising scheme to address high-ISO long-exposure noise, which sometimes spatially shows a blob appearance, employing a blob reduction procedure as a cheap preprocessing for conventional denoising methods. We apply the proposed denoising methods to real-world noisy images as well as standard images that are corrupted by real noise. The experimental results demonstrate the superiority of the proposed methods over state-of-the-art denoising methods
A Regularization Term Based on a Discrete Total Variation for Mathematical Image Processing
In this paper, a new regularization term is proposed to solve mathematical
image problems. By using difference operators in the four directions;
horizontal, vertical and two diagonal directions, an estimation of derivative
amplitude is found. Based on the new obtained estimation, a new regularization
term will be defined, which can be viewed as a new discretized total variation
(TVprn) model. By improving TVprn, a more effective regularization term is
introduced. By finding conjugate of TVprn and producing vector fields with
special constraints, a new discretized TV for two dimensional discrete
functions is proposed (TVnew). The capability of the new TV model to solve
mathematical image problems is examined in some numerical experiments. It is
shown that the new proposed TV model can reconstruct the edges and corners of
the noisy images better than other TVs. Moreover, two test experiments of
resolution enhancement problem are solved and compared with some other
different TVs
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