In this paper we show some results of image recognition tests in which a testee looks at an image and tell if he/she can recognize a certain figure in it or not. When we study digital halftoning process, it is important to discuss the resolution of the human eye, or eye and brain, from the viewpoint of image recognition.
Shigeru Kitakubo, Yasushi Hoshino, Shi-Biao Xu, "Evaluation of Graininess for Digital Halftone Images Based on Human Visual Sensitivity" in Proc. IS&T Int'l Conf. on Digital Printing Technologies (NIP20), 2004, pp 435 - 438, https://doi.org/10.2352/ISSN.2169-4451.2004.20.1.art00096_1