Revisit 1D Total Variation restoration problem with new real-time algorithms for signal and hyper-parameter estimations

원문 초록

1D Total Variation (TV) denoising, considering the data fidelity and the Total Variation (TV) regularization, proposes a good restored signal preserving shape edges. The main issue is how to choose the weight $\lambda$ balancing those two terms. In practice, this parameter is selected by assessing a list of candidates (e.g. cross validation), which is inappropriate for the real time application. In this work, we revisit 1D Total Variation restoration algorithm proposed by Tibshirani and Taylor. A heuristic method is integrated for estimating a good choice of $\lambda$ based on the extremums number of restored signal. We propose an offline version of restoration algorithm in O(n log n) as well as its online implementation in O(n). Combining the rapid algorithm and the automatic choice of $\lambda$, we propose a real-time automatic denoising algorithm, providing a large application fields. The simulations show that our proposition of $\lambda$ has a similar performance as the states of the art.