[ 1 ] Guo J M, Sankarasrinivasan S. Digital halftone database (DHD): A comprehensive analysis on halftone types [ C ]∥ 2018 Asia - Pacific Signal and Information Processing Association Annual Summit and Conference (APSIPA ASC). Honolulu, HI, USA. IEEE, 2019: 1091 - 1099. [2]张燕, 张二虎. 图像逆半色调技术研究[J]. 西安理工大学学报, 2017, 33(3): 282-289. [3]孔月萍, 曾平, 何波, 等. LUT 与 Elman 网络相结合的图像逆半调算法[J]. 中国图象图形学报, 2007, 12(11): 1988-1991. [4]Xiong Z X, Orchard M T, Ramchandran K. Inverse halftoning using wavelets[J]. IEEE Transactions on Image Processing, 1999, 8(10): 1479-1483. [5]Mese M, Vaidyanathan P P. Look-up table (LUT) method for inverse halftoning[J]. IEEE Transactions on Image Processing, 2001, 10(10): 1566-1578. [6]Hou X X, Qiu G P. Image companding and inverse halftoning using deep convolutional neural networks[EB/OL]. (2017-07-01)[2023-07-15]. https:∥arxiv.org/abs/170700116. [7]Xiao Y, Pan C, Zheng Y, et al. Gradient-guided DCNN for inverse halftoning and image expanding[C]∥Asian Conference on Computer Vision. Cham: Springer International Publishing, 2019: 207-222. [8]Yuan J, Pan C, Zheng Y, et al. Gradient-guided residual learning for inverse halftoning and image expanding[J]. IEEE Access, 2019, 8: 50995-51007. [9]Xia M, Wong T T. Deep inverse halftoning via progressively residual learning[C]∥Computer Vision-ACCV 2018: 14th Asian Conference on Computer Vision. Perth, Australia. Cham: Springer International Publishing, 2019: 523-539. [10]Son C H. Inverse halftoning through structure-aware deep convolutional neural networks[J]. Signal Processing, 2020, 173: 107591.