“…A very popular algorithm to solve such saddle point problems is the primal-dual hybrid gradient (PDHG) 1 algorithm [36,20,12,35,13,14]. It has been used to solve a vast amount of stateof-the-art problems-to name a few examples in imaging: image denoising with the structure tensor [21], total generalized variation denoising [10], dynamic regularization [6], multi-modal medical imaging [26], multi-spectral medical imaging [42], computation of non-linear eigenfunctions [25], regularization with directional total generalized variation [28]. Its popularity stems from two facts: First, it is very simple and therefore easy to implement.…”