correct RandomFlipOp (#1796)

Co-authored-by: Nroot <root@bjyz-sys-gpu-kongming0.bjyz.baidu.com>

configs/_base_/models/yolov3_darknet53.yml

@@ -3,6 +3,7 @@ pretrain_weights: https://paddle-imagenet-models-name.bj.bcebos.com/DarkNet53_pr
 weights: output/yolov3_darknet/model_final
 use_fine_grained_loss: false
 load_static_weights: True
+norm_type: sync_bn
 
 YOLOv3:
   backbone: DarkNet
@@ -13,7 +14,6 @@ YOLOv3:
 DarkNet:
   depth: 53
   return_idx: [2, 3, 4]
-  norm_type: sync_bn
 
 YOLOv3FPN:
   feat_channels: [1024, 768, 384]
@@ -28,7 +28,7 @@ YOLOv3Head:
 YOLOv3Loss:
   ignore_thresh: 0.7
   downsample: [32, 16, 8]
-  label_smooth: true
+  label_smooth: false
 
 BBoxPostProcess:
   decode:

configs/_base_/runtime.yml

 use_gpu: true
-log_iter: 50
+log_iter: 20
 save_dir: output
 snapshot_epoch: 2

ppdet/data/transform/operator.py

@@ -523,7 +523,10 @@ class RandomFlipOp(BaseOperator):
         return image[:, ::-1, :]
 
     def apply_bbox(self, bbox, width):
-        bbox[:, 0::2] = width - bbox[:, 0::2] - 1
+        oldx1 = bbox[:, 0].copy()
+        oldx2 = bbox[:, 2].copy()
+        bbox[:, 0] = width - oldx2 - 1
+        bbox[:, 2] = width - oldx1 - 1
         return bbox
 
     def apply(self, sample, context=None):