updates

utils/utils.py

@@ -224,6 +224,7 @@ def compute_ap(recall, precision):
     # Returns
         The average precision as computed in py-faster-rcnn.
     """
+
     # Append sentinel values to beginning and end
     mrec = np.concatenate(([0.], recall, [1.]))
     mpre = np.concatenate(([0.], precision, [0.]))
@@ -232,11 +233,15 @@ def compute_ap(recall, precision):
     for i in range(mpre.size - 1, 0, -1):
         mpre[i - 1] = np.maximum(mpre[i - 1], mpre[i])
 
-    # Calculate area under PR curve, looking for points where x axis (recall) changes
-    i = np.where(mrec[1:] != mrec[:-1])[0]
+    # Integrate area under curve
+    method = 'interp'  # methods: 'continuous', 'interp'
+    if method == 'interp':
+        x = np.linspace(0, 1, 101)  # 101-point interp (COCO)
+        ap = np.trapz(np.interp(x, mrec, mpre), x)  # integrate
+    else:  # 'continuous'
+        i = np.where(mrec[1:] != mrec[:-1])[0]  # points where x axis (recall) changes
+        ap = np.sum((mrec[i + 1] - mrec[i]) * mpre[i + 1])  # area under curve
 
-    # Sum (\Delta recall) * prec
-    ap = np.sum((mrec[i + 1] - mrec[i]) * mpre[i + 1])
     return ap