An Improved LOT Model for Image Restoration

作者：Dong Fangfang; Liu Zhen^*; Kong Dexing; Liu Kefeng

来源：Journal of Mathematical Imaging and Vision, 2009, 34(1): 89-97.

DOI：10.1007/s10851-008-0132-z

• Image restoration
• LOT model
• The staircase effect
• The dual formulation
• Edge indicator function

Some second order PDE-based image restoration models such as total variation (TV) minimization or ROF model of Rudin et al. (Physica D 60, 259-268, 1992) can easily give rise to staircase effect, which may produce undesirable blocky image. LOT model proposed by Laysker, Osher and Tai (IEEE Trans. Image Process. 13(10), 1345-1357, 2004) has alleviated the staircase effect successfully, but the algorithms are complicated due to three nonlinear second-order PDEs to be computed, besides, when we have no information about the noise, the model cannot preserve edges or textures well. In this paper, we propose an improved LOT model for image restoration. First, we smooth the angle theta rather than the unit normal vector n, where n=(cos theta,sin theta). Second, we add an edge indicator function in order to preserve fine structures such as edges and textures well. And then the dual formulation of TV-norm and TV (g) -norm are used in the numerical algorithms. Finally, some numerical experiments prove our proposed model and algorithms to be effective.

• 出版日期2009-5
• 单位浙江工业大学; 浙江大学