Table 1. Pixel filtering modes.

Artifact type	Activity region type	Pixel to be filtered	Mode of filtering
Fig 4(i)	Smooth-Smooth	{p4, p5, p6, p7, p8, p9, p10, p11}	1
Fig 4(ii)	Smooth–Non-smooth	{p5, p6, p7, p8, p9, p10}	2
Fig 4(iii)	Non-smooth- Non-smooth	{p7, p8}	3