Multispectral image denoising with optimized vector non-local mean filter

TL;DR

This paper introduces an optimized vector non-local mean filter for multispectral image denoising, leveraging parameter tuning via Stein's Unbiased Risk Estimator to improve noise reduction while reducing computational complexity.

Contribution

It extends the non-local means filter to the vector case for multispectral images and proposes a dynamic parameter optimization framework using SURE.

Findings

Improved PSNR in multispectral image denoising.

Reduced computational complexity compared to traditional NLM.

Effective noise attenuation while preserving image details.

Abstract

Nowadays, many applications rely on images of high quality to ensure good performance in conducting their tasks. However, noise goes against this objective as it is an unavoidable issue in most applications. Therefore, it is essential to develop techniques to attenuate the impact of noise, while maintaining the integrity of relevant information in images. We propose in this work to extend the application of the Non-Local Means filter (NLM) to the vector case and apply it for denoising multispectral images. The objective is to benefit from the additional information brought by multispectral imaging systems. The NLM filter exploits the redundancy of information in an image to remove noise. A restored pixel is a weighted average of all pixels in the image. In our contribution, we propose an optimization framework where we dynamically fine tune the NLM filter parameters and attenuate its computational complexity by considering only pixels which are most similar to each other in computing a restored pixel. Filter parameters are optimized using Stein's Unbiased Risk Estimator (SURE) rather than using ad hoc means. Experiments have been conducted on multispectral images corrupted with additive white Gaussian noise and PSNR and similarity comparison with other approaches are provided to illustrate the efficiency of our approach in terms of both denoising performance and computation complexity.