Image denoising is still a challenge of image processing. Buades et al. proposed a nonlocal means （NL-means） approach. This method had a remarkable denoising results at high expense of computational cost. In this pa...Image denoising is still a challenge of image processing. Buades et al. proposed a nonlocal means （NL-means） approach. This method had a remarkable denoising results at high expense of computational cost. In this paper, We compared several fast non-local means methods, and proposed a new fast algorithm. Numerical experiments showed that our algorithm considerably reduced the computational cost, and obtained visually pleasant images.展开更多
This paper establishes a global Carleman inequality of parabolic equations with mixed boundary conditions and an estimate of the solution. Further, we prove exact controllability of the equation by controls acting on ...This paper establishes a global Carleman inequality of parabolic equations with mixed boundary conditions and an estimate of the solution. Further, we prove exact controllability of the equation by controls acting on an arbitrarily given subdomain or subboundary.展开更多
In this paper, three numerical schemes with high accuracy for the coupled Schrodinger equations are studied. The conserwtive properties of the schemes are obtained and the plane wave solution is analysised. The split ...In this paper, three numerical schemes with high accuracy for the coupled Schrodinger equations are studied. The conserwtive properties of the schemes are obtained and the plane wave solution is analysised. The split step Runge-Kutta scheme is conditionally stable by linearized analyzed. The split step compact scheme and the split step spectral method are unconditionally stable. The trunction error of the schemes are discussed. The fusion of two solitions colliding with different β is shown in the figures. The numerical experments demonstrate that our algorithms are effective and reliable.展开更多
In this paper, we propose a new time-dependent model for solving total variation （TV） minimization problems in image restoration. The main idea is applying a priori smoothness on the solution image. Five different B...In this paper, we propose a new time-dependent model for solving total variation （TV） minimization problems in image restoration. The main idea is applying a priori smoothness on the solution image. Five different BCs are introduced and analyzed. 2D numerical experimental results by explicit numerical schemes are discussed.展开更多
In this paper, we propose new pretreat models for total variation （TV） minimization problems in image deblurring and denoising. Specially, blur operator is considered as useful information in restoration. New models...In this paper, we propose new pretreat models for total variation （TV） minimization problems in image deblurring and denoising. Specially, blur operator is considered as useful information in restoration. New models in form is equivalent to pretreat the initial value by image blur operator. We successfully get a new （L. Rudin, S. Osher, and E. Fatemi） ROF model, a new level set motion model and a new anisotropic diffusion model respectively. Numerical experiments demonstrate that, under the same stopping rule, the proposed methods significantly accelerate the convergence of the toothed, save computation time and get the same restored effect.展开更多
Image restoration is a fundamental problem in image processing. Blind image restoration has a great value in its practical application. However, it is not an easy problem to solve due to its complexity and difficulty....Image restoration is a fundamental problem in image processing. Blind image restoration has a great value in its practical application. However, it is not an easy problem to solve due to its complexity and difficulty. In this paper, we combine our robust algorithm for known blur operator with an alternating minimization implicit iterative scheme to deal with blind deconvolution problem, recover the image and identify the point spread function（PSF）. The only assumption needed is satisfy the practical physical sense. Numerical experiments demonstrate that this minimization algorithm is efficient and robust over a wide range of PSF and have almost the same results compared with known PSF algorithm.展开更多
基金supported by the Tianyuan Special Funds of the NSFC (Grant No. 11126085)the Fundamental Research Funds for the Central Universities (Grant No. 11CX04060A)The third author is supported by Natural Science Foundation of China University of Petroleum (East China) (Grant No. Y080805)
文摘Image denoising is still a challenge of image processing. Buades et al. proposed a nonlocal means （NL-means） approach. This method had a remarkable denoising results at high expense of computational cost. In this paper, We compared several fast non-local means methods, and proposed a new fast algorithm. Numerical experiments showed that our algorithm considerably reduced the computational cost, and obtained visually pleasant images.
文摘This paper establishes a global Carleman inequality of parabolic equations with mixed boundary conditions and an estimate of the solution. Further, we prove exact controllability of the equation by controls acting on an arbitrarily given subdomain or subboundary.
文摘In this paper, three numerical schemes with high accuracy for the coupled Schrodinger equations are studied. The conserwtive properties of the schemes are obtained and the plane wave solution is analysised. The split step Runge-Kutta scheme is conditionally stable by linearized analyzed. The split step compact scheme and the split step spectral method are unconditionally stable. The trunction error of the schemes are discussed. The fusion of two solitions colliding with different β is shown in the figures. The numerical experments demonstrate that our algorithms are effective and reliable.
基金Supported by the National Natural Science Foundation of China (No. 10726035, 10801049)Foundation of North China Electric Power University
文摘In this paper, we propose a new time-dependent model for solving total variation （TV） minimization problems in image restoration. The main idea is applying a priori smoothness on the solution image. Five different BCs are introduced and analyzed. 2D numerical experimental results by explicit numerical schemes are discussed.
基金Supported by Youth Foundation of Tianyuan Mathematics,National Natural Science Foundation of China(Grant No. 10926037)the National Natural Science Foundation of China (Grant No.10771210 and No.11001239)partially supported by Singapore MOE Grant T207B2202,Singapore NRF2007IDM-IDM002-010
文摘In this paper, we propose new pretreat models for total variation （TV） minimization problems in image deblurring and denoising. Specially, blur operator is considered as useful information in restoration. New models in form is equivalent to pretreat the initial value by image blur operator. We successfully get a new （L. Rudin, S. Osher, and E. Fatemi） ROF model, a new level set motion model and a new anisotropic diffusion model respectively. Numerical experiments demonstrate that, under the same stopping rule, the proposed methods significantly accelerate the convergence of the toothed, save computation time and get the same restored effect.
文摘Image restoration is a fundamental problem in image processing. Blind image restoration has a great value in its practical application. However, it is not an easy problem to solve due to its complexity and difficulty. In this paper, we combine our robust algorithm for known blur operator with an alternating minimization implicit iterative scheme to deal with blind deconvolution problem, recover the image and identify the point spread function（PSF）. The only assumption needed is satisfy the practical physical sense. Numerical experiments demonstrate that this minimization algorithm is efficient and robust over a wide range of PSF and have almost the same results compared with known PSF algorithm.
