From 975bc52d3b23c247ee1159926cb8bff531dc2f2c Mon Sep 17 00:00:00 2001
From: shaharzuler <shahar.zuler@gmail.com>
Date: Sat, 16 Jan 2021 15:24:44 +0200
Subject: [PATCH] Updated intersect_area() calculation - fixed negative IoU
 values

Replaced np.clip() with separate minimum-maximum check, since np.clip() doesnt verify a_min<a_max. np.clip() sometimes caused negative IoU intersection values.
---
 mean_average_precision/utils/bbox.py | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/mean_average_precision/utils/bbox.py b/mean_average_precision/utils/bbox.py
index 3cdb5f9..29219aa 100644
--- a/mean_average_precision/utils/bbox.py
+++ b/mean_average_precision/utils/bbox.py
@@ -23,7 +23,11 @@ def intersect_area(box_a, box_b):
     min_xy = np.maximum(resized_A[:, :, :2], resized_B[:, :, :2])
 
     diff_xy = (max_xy - min_xy)
-    inter = np.clip(diff_xy, a_min=0, a_max=np.max(diff_xy))
+    inter = np.maximum(diff_xy, 0)
+    inter_max = np.max(diff_xy)
+    if inter_max > 0:
+        inter = np.minimum(inter_max, inter)
+    
     return inter[:, :, 0] * inter[:, :, 1]
 
 
@@ -46,4 +50,4 @@ def jaccard(box_a, box_b):
     area_a = area_a[:, np.newaxis]
     area_b = area_b[np.newaxis, :]
     union = area_a + area_b - inter
-    return inter / union
\ No newline at end of file
+    return inter / union