3D Winding Number: Theory and Application to Medical Imaging

Table 3

Correspondence between the sign of the Hessian determinant and winding number for critical points in 3D.

3D	Sign(det𝐻)	Winding number
Minimum	+	+4𝜋
1-saddle	−	−4𝜋
2-saddle	+	+4𝜋
Maximum	−	−4𝜋