Automatic Traffic Data Collection under Varying Lighting and Temperature Conditions in Multimodal Environments: Thermal versus Visible Spectrum Video-Based Systems

Table 4

Detection and classification performance for different lighting conditions—thermal and regular video.

Lighting condition	Thermal video				Regular video
	Number of road users present	Number of missed instances/miss rate	Classification precision	Classification recall	Road user present	Number of missed instances/miss rate	Classification precision	Classification recall
	Vehicle detection and classification
Daytime
Overcast	121	0/0.0%	53.3%	97.0%	192	0/0.0%	78.9%	99.3%
Sun, little shadow	52	2/3.8%	46.3%	100.0%	74	0/0.0%	67.9%	100.0%
Sun, strong shadows	77	0/0.0%	44.2%	100.0%	83	3/3.6%	55.0%	100.0%
Nighttime
High visibility	102	1/1.0%	66.7%	91.2%	102	4/3.9%	74.5%	97.6%
Medium visibility	249	4/1.6%	99.0%	96.2%	241	11/4.6%	97.2%	99.5%
Low visibility	42	1/2.4%	56.3%	96.4%	42	2/4.8%	91.4%	100.0%
	Cyclist detection and classification
Daytime
Overcast	26	1/3.8%	36.1%	81.3%	38	1/2.6%	30.9%	96.7%
Sun, little shadow	46	1/2.2%	95.8%	54.8%	57	4/7.0%	87.8%	78.3%
Sun, strong shadows	68	4/5.9%	90.3%	50.0%	67	11/16.4%	63.0%	68.0%
Nighttime
High visibility	44	1/2.3%	70.2%	93.0%	44	36/81.8%	42.9%	37.5%
Medium visibility	12	0/0.0%	64.7%	100.0%	12	12/100.0%	0.0%	Invalid
Low visibility	10	0/0.0%	69.2%	90.0%	10	10/100.0%	Invalid	Invalid
	Pedestrian detection and classification
Daytime
Overcast	314	9/2.9%	98.3%	68.5%	356	14/3.9%	99.1%	68.3%
Sun, little shadow	78	2/2.6%	82.1%	56.1%	63	0/0.0%	93.8%	66.2%
Sun, strong shadows	118	9/7.6%	100.0%	46.8%	130	19/14.6%	86.6%	59.2%
Nighttime
High visibility	149	5/3.4%	97.8%	68.9%	149	109/73.1%	90.0%	25.7%
Medium visibility	85	3/3.5%	94.5%	94.5%	77	68/88.3%	100.0%	14.3%
Low visibility	286	4/1.4%	99.5%	89.5%	286	278/97.2%	Invalid	0.0%
	Total detection and classification
			Accuracy				Accuracy
Daytime
Overcast	461	10/2.2%	74.9%		586	15/2.6%	79.1%
Sun, little shadow	176	5/1.8%	66.2%		194	4/2.1%	80.2%
Sun, strong shadows	263	13/4.9%	62.8%		280	33/11.8%	69.1%
Nighttime
High visibility	295	7/2.4%	79.4%		295	159/50.5%	74.0%
Medium visibility	346	7/2.0%	96.1%		330	91/27.6%	96.8%
Low visibility	338	5/1.5%	90.3%		338	290/85.8%	91.4%