View full-text article in PMC J Imaging. 2021 Nov 24;7(12):248. doi: 10.3390/jimaging7120248 Search in PMC Search in PubMed View in NLM Catalog Add to search Copyright and License information © 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/). PMC Copyright notice Algorithm 1 Learned Primal-Dual reconstruction. 1:Given: g, NLPD 2:Set: R(·)=A*(·)||A||2 3:h(0)=Ξϕ0(g) 4:fg(0)=R(h(0)) 5:f(0)=Λθ0(fg(0)) 6:fori=1, ⋯, NLPD−1do 7: hf(i−1)=A(f(i−1)) 8: h(i)=h(i−1)+Ξϕi(g,h(0),⋯,h(i−1),hf(i−1)) 9: fg(i)=R(h(i)) 10: f(i)=f(i−1)+Λθi(f(0),⋯,f(i−1),fg(i)) 11:end for 12:returnf(i)