Closed Contour Specular Reflection Segmentation in Laparoscopic Images

Table 1

The hybrid closed contour algorithm achieves the best results compared to thresholding techniques in terms of the Jaccard index and sensitivity. Note the high value for 𝑄₁ and the sensitivity; this increase is caused by the reflections of Type 3 (T3) which are missed by the other algorithms.

Algorithm	𝐹Jaccard	𝑄1	𝑄3	Sensitivity				PPV
				T1	T2	T3	Avg.
Gray-level thresholding	0.55	0.26	0.80	1	0.96	0.10	0.74	0.96
Specular peak thresholding	0.60	0.38	0.87	1	0.81	0	0.61	0.99
Cone thresholding	0.60	0.37	0.81	1	0.91	0.10	0.70	0.99
Hybrid closed contour	0.66	0.55	0.82	1	0.97	0.69	0.90	0.96

The bold font highlights the best result for each category.