“…This variant of the projected gradient method involves a Barzilai-Borwein steplength (Barzilai and Borwein, 1988) and a linesearch to ensure convergence. Due to its simplicity and efficiency, SPG is used for inverse problems in engineering applications (Birgin, Martínez, and Raydan, 2014, section 4), including image deblurring (Bonettini, Zanella, and Zanni, 2008) and radiology (Kolehmainen, Vanne, Siltanen, Jarvenpaa, Kaipio, Lassas, and Kalke, 2006;Kolehmainen, Vanne, Siltanen, Järvenpää, Kaipio, Lassas, and Kalke, 2007).…”