vault backup: 2025-01-14 01:30:56

.obsidian/workspace.json

@@ -45,7 +45,7 @@
                 "file": "Biometric Systems/slides/LEZIONE11_Fingerprints.pdf",
                 "page": 35,
                 "left": -14,
-                "top": 341,
+                "top": 491,
                 "zoom": 1.0875
               },
               "icon": "lucide-file-text",

Biometric Systems/notes/11. Fingerprints.md

@@ -100,7 +100,7 @@ Once a fingerprint has been segmentated we can start extracting **macro-features
 ![[Pasted image 20241127135348.png]]
 
 ##### Directional map
-The local orientation of the ridge line in the position [i, j] is defined as the angle $\theta(i,j)$ formed by considering the horizontal line at that point, and a point on the ridge line sufficiently closer to [i, j].
+~~The local orientation of the ridge line in the position [i, j] is defined as the angle $\theta(i,j)$ formed by considering the horizontal line at that point, and a point on the ridge line sufficiently closer to [i, j].~~
 ![[Pasted image 20241127224325.png]]
 - most approaches use a grid measure (instead of measuring at each point)
 - the directional image D is a matrix in which each element denotes the average orientation of the ridge (of the tangent to the ridge) in a neighborhood of $[x_{i}, y_{i}]$