Search

Aeroheating-induced intensity nonuniformity effects severely influence the effective performance of an infrared (IR) imaging system in high-speed flight. In this paper, we propose a new approach to the correction of intensity nonuniformity in IR images. The basic assumption is that the low-frequency intensity bias is additive and smoothly varying so that it can be modeled as a bivariate polynomial and estimated by using an isotropic total variation (TV) model. A half quadratic penalty method is applied to the isotropic form of TV discretization. And an alternating minimization algorithm is adopted for solving the optimization model. The experimental results of simulated and real aerothermal images show that the proposed correction method can effectively improve IR image quality. [ABSTRACT FROM AUTHOR]

Abstract: A poor inherent resolution capability of the passive millimeter-wave (PMMW) imaging becomes a problem in many applications. This paper proposes a parametric blind deconvolution approach for improving the resolution of PMMW images with low signal-to-noise ratio. Image deconvolution is a challenging ill-posed inverse problem when only partial knowledge of the point spread function (PSF) is available, therefore, regularization techniques need to be used. To restore high quality PMMW image, framelet based regularization constraint is incorporated into parametric blind PMMW image deconvolution framework, which is modeled as an alternative optimization problem about the image and the PSF. The PSF is modeled as a parametric form to restrict the PSF solution space. Furthermore, the split Bregman iteration is used to solve the resulting minimization problem. Comparative experimental results on simulated and real PMMW images show that the proposed method can effectively suppress noise, reduce artifacts, and improve the spatial resolution. [Copyright &y& Elsevier]

Abstract: In the paper, a multiframe blind image deconvolution method based on total variation and framelet regularizer is proposed. An adapted version of the split Bregman method is proposed to efficiently solve the resulting minimization problems. In each iteration, four sub-problems need to be solved, one of which can be very efficiently and easily solved via fast Fourier transform implementation or closed form solution. Both simulated noisy and blurred frames and real degraded frames are used to verify the effectiveness of the proposed method. Comparative experimental results show that the proposed method can efficiently remove the blur and noises and restore high quality sharp image. [Copyright &y& Elsevier]

Imaging from a degenerated push broom scanner usually leads to an undesired stripe noise which seriously affected the image quality. The original unidirectional total variation ( UTV ) model produces a poor performance on stripe images which has a strong contrast between cleaning image area and striped area or different image area. In this research, a new destriping method which combines TV - Stokes and UTV model ( UTV-Stokes for short) has been developed to overcome the disadvantages of UTV . By distinguishing stripe region and no-stripe region in calculation, this method can avoid excessive smoothing or residual's appearing through less filtering. Comparative results on simulated and real striped images taken with MODIS and hyperspectral imaging systems demonstrated that the proposed method not only can handle various stripe images with different noise intensity but also can preserve the edge and detailed information. [ABSTRACT FROM AUTHOR]

Abstract: Multi-detectors imaging system often suffers from the problem of the stripe noise, which greatly degrades the quality of the resulting images. To better remove stripe noise and preserve the edge and texture information, a robust destriping algorithm with spatially adaptive unidirectional total variation (SAUTV) model is introduced. The spatial information of the striping noise is detected by using the stripe indicator called difference eigenvalue, and a weighted parameter determined by the difference eigenvalue information is added to constrain the regularization strength of the UTV regularization. The proposed algorithm can effectively remove the stripe noise and preserve the edge and detailed information. Moreover, it becomes more robust with the change of the regularization parameter. Split Bregman method is utilized to efficiently solve the resulting minimization problem. Comparative results on simulated and real striped images taken with two kinds of imaging systems are reported. [Copyright &y& Elsevier]