Add eccentricity and angle computation

examples/gallery/plot_fit-ellipse.py

@@ -29,6 +29,6 @@ def plot(geoms):
     plt.show()
 
 geom = EXAMPLE_GEOMETRY
-ellipse = fitEllipse(geom)
-
+ellipse, eccentricity, theta = fitEllipse(geom)
+print('Eccentricity {} and Angle {}'.format(eccentricity, theta))
 plot([geom, ellipse])

tathu/geometry/utils.py

@@ -81,7 +81,13 @@ def fitEllipse(polygon):
     # Fit ellipse
     (xc,yc), (a,b), theta = cv2.fitEllipse(coords)
 
-    return ellipse2polygon(xc, yc, a * 0.5, b * 0.5, -theta)
+    # Compute eccentricity
+    major_ax, minor_ax = a, b
+    if a < b: major_ax, minor_ax = b, a
+    eccentricity = np.sqrt(1 - ((minor_ax * minor_ax)/(major_ax * major_ax)))
+
+    return ellipse2polygon(xc, yc, a * 0.5, b * 0.5, -theta), eccentricity, theta
+
 
 def getRadiusFromCircle(polygon):
     # Extract coordinates to NumpyArray in order to user opencv2.minEnclosingCircle

tathu/tracking/descriptors.py

@@ -266,4 +266,15 @@ def describe(self, image, systems):
         # v component
         descriptor = StatisticalDescriptor(stats=['mean'], prefix='v_')
         descriptor.describe(v, systems)
-
+
+class MaxValueGeolocationDescriptor():
+    '''
+    This class implements a descriptor that calculates geolocation
+    (i.e. latitude and longitude coordinates) of the maximum value
+    found within the system boundaries.
+    '''
+    def __init__(self):
+        pass
+
+    def describe(self, image, systems):
+        pass