436031.fig.002a
(a) First pair
436031.fig.002b
(b) Second pair
436031.fig.002c
(c) Third pair
436031.fig.002d
(d) Fourth pair
Figure 2: Four monoscopic image pairs with the same “computer” image content: ((a)–(c)) three pairs of distorted images; (d) reference image pairs. The regions marked in red circle can clearly show the different JPEG compressive qualities of every image.