Closed Contour Specular Reflection Segmentation in Laparoscopic Images

Figure 3

Parameter optimization using the Jaccard index. The dot labels the optimal parameter values. The optimal parameters are used in the evaluation.

(a) Parameter space of the cone thresholding algorithm spanned by 𝑥₀ and 𝑎. For visualization, the 3-dimensional parameter spaces 𝑥₀, 𝑎, and 𝑐 were reduced to the slice containing the optimal parameters 𝑥₀=0.89, 𝑎=0.89, and 𝑐=0.92

(b) Parameter space of the specular peak thresholding algorithm spanned by 𝜎 and 𝑐. The maximal Jaccard index is located at 𝜎=3.4 and 𝑐=0.92

(c) Parameter space of gray-level thresholding spanned by 𝑡_spec and 𝑐. The maximum Jaccard index is labeled by the red dot. 𝑡_spec=0.94 and 𝑐=0.92