Figure 9
From: Detection of tampered region for JPEG images by using mode-based first digit features
The probability distributions of OL and DE for JPEG + JPEG manipulation: (a) The JPEG + JPEG manipulation with the JPEG quality factors QF 1 = 50 and QF 2 = 80; (b) The JPEG + JPEG manipulation with the JPEG quality factors QF 1 , =65 and QF 2 = 90. In each panel, the red dashed curve corresponds to the probability distribution of DE, and the blue solid curve denotes the probability distribution of OL. See also Tables4 and5.