Color Enhancement in Endoscopic Images Using Adaptive Sigmoid Function and Space Variant Color Reproduction

Table 11

Comparisons of the measurement of uniform distribution based on entropy with other related works.

Image number	Measurement of entropy
	Original	AHE [11]	CLAHE [12]	HBF [13]	BPDFHE [14]	Proposed
1	7.25	6.68	7.38	7.33	7.41	7.46
2	7.21	6.47	7.48	7.33	7.44	7.57
3	7.11	6.38	7.34	7.31	7.38	7.51
4	6.52	4.87	7.11	6.77	7.51	7.70
Average of 60 endoscopic images	7.41	7.01	7.68	7.31	7.75	7.91