Add Soft-NMS for testing RetinaNet. (#670)

Summary:
Soft-NMS is present in test.py, but it is missing in test_retinanet.py.
Pull Request resolved: https://github.com/facebookresearch/Detectron/pull/670

Reviewed By: rbgirshick

Differential Revision: D10035825

Pulled By: ir413

fbshipit-source-id: c49ac7e595b32d2ac757815df4add1c644a34027

detectron/core/test_retinanet.py

@@ -164,8 +164,17 @@ def im_detect_bbox(model, im, timers=None):
     for cls, boxes in boxes_all.items():
         cls_dets = np.vstack(boxes).astype(dtype=np.float32)
         # do class specific nms here
-        keep = box_utils.nms(cls_dets, cfg.TEST.NMS)
-        cls_dets = cls_dets[keep, :]
+        if cfg.TEST.SOFT_NMS.ENABLED:
+            cls_dets, keep = box_utils.soft_nms(
+                cls_dets,
+                sigma=cfg.TEST.SOFT_NMS.SIGMA,
+                overlap_thresh=cfg.TEST.NMS,
+                score_thresh=0.0001,
+                method=cfg.TEST.SOFT_NMS.METHOD
+            )
+        else:
+            keep = box_utils.nms(cls_dets, cfg.TEST.NMS)
+            cls_dets = cls_dets[keep, :]
         out = np.zeros((len(keep), 6))
         out[:, 0:5] = cls_dets
         out[:, 5].fill(cls)