Printed document contains intrinsic features of printer,the extraction of intrinsic features is critical in printer forensics.We discover that the extracted geometric distortion features of document page can be used in printer forensics.Based on this,a projective transformation is employed to model the geometric distortion of document page.The pre-processing process is adopted to get the set of feature point pair,the least squares method is employed to estimate the parameters of the model,and the residual e...