A BigBiGAN-Based Loop Closure Detection Algorithm for Indoor Visual SLAM

Algorithm 2

Loop closure main component.

Input: RGB image
Output: a loop closure detection result
(1)	img ⟵ GetRGBgray (RGB)
(2)	x ⟵ FeatureExtraction(img)
(3)	FOR i = 1 to BoWD. Length() DO
(4)	IF x = = BoWD[i] THEN
(5)	D ⟵ TRUE
(6)	ENDFOR
(7)	IF D THEN
(8)	FOR i = 1 to BoWG. Length() DO
(9)	IF x = = BoWG[i] THEN
(10)	G ⟵ TRUE
(11)	END FOR
(12)	ELSE
(13)	RETURN FALSE
(14)	END IF
(15)	IF G THEN
(16)	L ⟵ ORBCheck(imgCollection[i], img)
(17)	ELSE
(18)	RETURN FALSE
(19)	END IF
(20)	IF L THEN
(21)	RETURN TRUE
(22)	ELSE
(23)	RETURN FALSE
(24)	END IF