fix bgr2ycbcr bug in color conversion

Author: xinntao

basicsr/data/paired_image_dataset.py

@@ -3,7 +3,7 @@
 
 from basicsr.data.data_util import paired_paths_from_folder, paired_paths_from_lmdb, paired_paths_from_meta_info_file
 from basicsr.data.transforms import augment, paired_random_crop
-from basicsr.utils import FileClient, imfrombytes, img2tensor, rgb2ycbcr
+from basicsr.utils import FileClient, bgr2ycbcr, imfrombytes, img2tensor
 from basicsr.utils.registry import DATASET_REGISTRY
 
 
@@ -87,8 +87,8 @@ def __getitem__(self, index):
 
         # color space transform
         if 'color' in self.opt and self.opt['color'] == 'y':
-            img_gt = rgb2ycbcr(img_gt, y_only=True)[..., None]
-            img_lq = rgb2ycbcr(img_lq, y_only=True)[..., None]
+            img_gt = bgr2ycbcr(img_gt, y_only=True)[..., None]
+            img_lq = bgr2ycbcr(img_lq, y_only=True)[..., None]
 
         # crop the unmatched GT images during validation or testing, especially for SR benchmark datasets
         # TODO: It is better to update the datasets, rather than force to crop