Automated optical inspection system for digital TV sets

EURASIP Journal on Advances in Signal Processing

Table 4 Results of the three comparison methods in image tests under variable illumination

Results of image tests--variable illumination
Number	Test	LAE	NCC	NCC-BB
1	Correct image	1657.58	473.74	84.16
2	Similar image 1	1722.57	348.17	84.04
3	Similar image 2	1724.35	348.17	84.04
4	Different image	1972.48	272.48	108.86
5	Constant black	1691.07	2.53	77.93
6	Constant white	1696.50	- 2.50	77.26

This table summarizes the results for LAE, NCC and NCC-BB comparison methods in image tests under variable illumination. NCC method showed the best vulnerability to these artificial and easily avoidable conditions in test environments. NCC-BB failed to detect the correct image because of its block-based properties--part where illumination is different dominated.