Poisson noise and blur removal using new edge-preserving penalties
Poisson Image Denoising Using Minimax Concave and Reweighted $\ell_1$ Penalties: Nonblind and Blind Approaches
Computer Vision and Pattern Recognition
Summary
Images taken in fields like medicine and astronomy often have noise and blur, making them hard to see clearly. The authors developed new ways to clean up these images by better preserving edges while removing noise and blur, even if the blurring pattern is unknown. They created and tested a math-based method that balances accuracy and speed for improving image quality. Their approach uses advanced penalty techniques and an optimization algorithm to restore images more effectively than before.
What this means in practice
- •For medical imaging specialists: Improve quality of noisy and blurred medical images by removing Poisson noise and unknown blur with enhanced edge preservation.
- •For astronomical image processors: Enhance astronomical observations by cleaning Poisson noisy and blurred images when the blurring function is unknown or partially known.
Authors
Reza Parvaz
Abstract
Images are important tools in various sciences. Despite the development of photo-taking tools, creating clear and image without noise remains challenging in practice. In particular, Poisson noise has an effect on medical and astronomical images, and reduces their quality. Additionally, blur is another factor that has an effect on image quality. The problem of image restoration becomes very complicated when we have no information about the Point Spread Function (PSF). These types of problems are known as blind case. However, in some images, such as some astronomical images, the type of PSF can be specified, and these types of problems are known as nonblind problems. Total Variation (TV) is a widely used method for solving such inverse problems, where the selection of the penalty function is the most critical factor that affects the method's performance. In this paper, to improve edge preservation, we employ a reweighted $\ell_1$-regularization of the fractional order derivative. Furthermore, we propose a nonblind and blind image deblurring approach under Poisson noise using the Minimax Concave Penalty (MCP), which is a continuous, sparsity promoting, and nearly unbiased regularizer. This formulation leads to a nonconvex optimization model. To solve the proposed model, we introduce an efficient numerical algorithm based on the Alternating Direction Method of Multipliers (ADMM) and provide an analysis of its convergence. Finally, the effectiveness of the proposed algorithm are demonstrated through extensive experiments on various images.