“…Identification of images that might have a common source can also be helpful in these investigations. The developments that have been started in the period of the previous review have not been stopped and have lead to a number of new methods and software packages [ [51] , [52] , [53] , [55] , [56] , [57] , [58] , [59] , [60] , [61] , [62] , [63] , [64] , [65] , [66] , [67] , [68] , [69] , [70] , [71] , [72] , [73] , [74] , [75] , [76] , [b] , [77] , [a] , [b] , [78] , [a] , [79] , [80] , [81] , [82] , [83] , [84] , [85] , [86] , [87] , [88] , [89] , [9] ]. The most used method is based on the estimation of a specific type of fixed pattern noise in an image that is caused by PRNU - Photo Response Non Uniformity .…”