▁is ▁generally ▁performed ▁on ▁the ▁resulting ▁binary ▁image ▁from ▁a ▁threshold ing ▁step , ▁but ▁it ▁can ▁be ▁applicable ▁to ▁gray - scale ▁and ▁color ▁images ▁as ▁well . ▁ ▁B lob s ▁may ▁be ▁counted , ▁filtered , ▁and ▁track ed . ▁ ▁B lob ▁extra ction ▁is ▁related ▁to ▁but ▁distinct ▁from ▁blob ▁detection . ▁ ▁Over view ▁▁ ▁A ▁graph , ▁containing ▁vertices ▁and ▁connecting ▁edges , ▁is ▁constructed ▁from ▁relevant ▁input ▁data . ▁The ▁vertices ▁contain ▁information ▁required ▁by ▁the ▁comparison ▁he ur istic , ▁while ▁the ▁edges ▁indicate ▁connected ▁' ne igh b ors '. ▁An ▁algorithm ▁travers es ▁the ▁graph , ▁label ing ▁the ▁vertices ▁based ▁on ▁the ▁connect ivity ▁and ▁relative ▁values ▁of ▁their ▁neighb ors . ▁Connect ivity ▁is ▁determined ▁by ▁the ▁medium ; ▁image ▁graphs , ▁for ▁example , ▁can ▁be ▁ 4 - connected ▁neighborhood ▁or ▁ 8 - connected ▁neighborhood . ▁ ▁Following ▁the ▁label ing ▁stage , ▁the ▁graph ▁may ▁be ▁partition ed ▁into ▁subsets , ▁after ▁which ▁the ▁original ▁information ▁can ▁be ▁recovered ▁and ▁processed ▁. ▁ ▁Definition ▁ ▁The ▁usage ▁of ▁the ▁term ▁connected - components ▁label ing ▁( CC L ) ▁and ▁its ▁definition ▁is ▁quite ▁consistent ▁in ▁the ▁academic ▁literature , ▁whereas ▁connected - components ▁analysis ▁( CC A ) ▁var ies ▁in ▁terms ▁of ▁both ▁termin ology ▁and ▁problem ▁definition . ▁ ▁Rosen feld ▁et ▁al . ▁define ▁connected ▁components ▁label ing ▁as ▁the ▁“ [ c ] re ation ▁of ▁a ▁l abeled ▁image ▁in