Initialise crop_gen in dataset mapper prior to tfm_gens so logs are c… (facebookresearch#207)

Summary:
…lear

Before no evidence was in the logs that crop_gen would occur before.
Small aesthetic improvement.

Purely additive PR.
Pull Request resolved: facebookresearch#207

Differential Revision: D18255481

Pulled By: ppwwyyxx

fbshipit-source-id: 3186656e8ae53d7a44ea8371db71b41cffcafe56

Author: RaymondCM

detectron2/data/dataset_mapper.py

@@ -1,5 +1,7 @@
 # Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved
 import copy
+import logging
+
 import numpy as np
 import torch
 from fvcore.common.file_io import PathManager
@@ -30,13 +32,14 @@ class DatasetMapper:
     """
 
     def __init__(self, cfg, is_train=True):
-        self.tfm_gens = utils.build_transform_gen(cfg, is_train)
-
         if cfg.INPUT.CROP.ENABLED and is_train:
             self.crop_gen = T.RandomCrop(cfg.INPUT.CROP.TYPE, cfg.INPUT.CROP.SIZE)
+            logging.getLogger(__name__).info("CropGen used in training: " + str(self.crop_gen))
         else:
             self.crop_gen = None
 
+        self.tfm_gens = utils.build_transform_gen(cfg, is_train)
+
         # fmt: off
         self.img_format     = cfg.INPUT.FORMAT
         self.mask_on        = cfg.MODEL.MASK_ON