Adds min probability threshold filter to RCNN proposals

luminoth/models/fasterrcnn/base_config.yml

@@ -193,6 +193,8 @@ rcnn:
     class_nms_threshold: 0.6
     # Maximum total detections for an image (sorted by score)
     total_max_detections: 300
+    # Minimum prob to be used as proposed object
+    min_prob_threshold: 0.5
 
   target:
     # Ratio between foreground and background samples in minibatch

luminoth/models/fasterrcnn/fasterrcnn_test.py

@@ -63,6 +63,7 @@ def setUp(self):
                   'class_max_detections': 100,
                   'class_nms_threshold': 0.6,
                   'total_max_detections': 300,
+                  'min_prob_threshold': 0.0,
                 },
                 'target': {
                   'foreground_fraction': 0.25,

luminoth/models/fasterrcnn/rcnn_proposal.py

@@ -38,6 +38,8 @@ def __init__(self, num_classes, config, name='rcnn_proposal'):
         self._class_nms_threshold = config.class_nms_threshold
         # Maximum number of detections to return.
         self._total_max_detections = config.total_max_detections
+        # Threshold probability
+        self._min_prob_threshold = config.min_prob_threshold or 0.0
 
     def _build(self, proposals, bbox_pred, cls_prob, im_shape):
         """
@@ -75,7 +77,14 @@ def _build(self, proposals, bbox_pred, cls_prob, im_shape):
         proposal_label_prob = tf.reduce_max(cls_prob, axis=1)
 
         # We are going to use only the non-background proposals.
-        proposal_filter = tf.greater_equal(proposal_label, 0)
+        non_background_filter = tf.greater_equal(proposal_label, 0)
+        # Filter proposals with less than threshold probability.
+        min_prob_filter = tf.greater_equal(
+            proposal_label_prob, self._min_prob_threshold
+        )
+        proposal_filter = tf.logical_and(
+            non_background_filter, min_prob_filter
+        )
 
         equal_shapes = tf.assert_equal(
             tf.shape(proposals)[0], tf.shape(bbox_pred)[0]

luminoth/models/fasterrcnn/rcnn_proposal_test.py

@@ -18,6 +18,7 @@ def setUp(self):
             'class_max_detections': 100,
             'class_nms_threshold': 0.6,
             'total_max_detections': 300,
+            'min_prob_threshold': 0.0,
         })
 
         self._equality_delta = 1e-03

luminoth/models/fasterrcnn/rcnn_test.py

@@ -42,6 +42,7 @@ def setUp(self):
                 'class_max_detections': 100,
                 'class_nms_threshold': 0.6,
                 'total_max_detections': 300,
+                'min_prob_threshold': 0.0,
             },
             'target': {
                 'foreground_fraction': 0.25,