Visualizer: make keypoint threshold configurable

Summary: Make the keypoint threshold a class member, so it can be changed.

Reviewed By: ppwwyyxx

Differential Revision: D30690598

fbshipit-source-id: 29499eaf12257e5bb4871ea318dc4ab5523d304e

Author: Jon Morton

detectron2/utils/visualizer.py

@@ -375,6 +375,7 @@ def __init__(self, img_rgb, metadata=None, scale=1.0, instance_mode=ColorMode.IM
             np.sqrt(self.output.height * self.output.width) // 90, 10 // scale
         )
         self._instance_mode = instance_mode
+        self.keypoint_threshold = _KEYPOINT_THRESHOLD
 
     def draw_instance_predictions(self, predictions):
         """
@@ -799,7 +800,7 @@ def draw_and_connect_keypoints(self, keypoints):
         for idx, keypoint in enumerate(keypoints):
             # draw keypoint
             x, y, prob = keypoint
-            if prob > _KEYPOINT_THRESHOLD:
+            if prob > self.keypoint_threshold:
                 self.draw_circle((x, y), color=_RED)
                 if keypoint_names:
                     keypoint_name = keypoint_names[idx]