Merge branch 'dygraph' into lite

requirements.txt

@@ -8,3 +8,4 @@ tqdm
 numpy
 visualdl
 python-Levenshtein
+opencv-contrib-python
\ No newline at end of file

setup.py

@@ -32,7 +32,7 @@ setup(
     package_dir={'paddleocr': ''},
     include_package_data=True,
     entry_points={"console_scripts": ["paddleocr= paddleocr.paddleocr:main"]},
-    version='2.0.2',
+    version='2.0.4',
     install_requires=requirements,
     license='Apache License 2.0',
     description='Awesome OCR toolkits based on PaddlePaddle （8.6M ultra-lightweight pre-trained model, support training and deployment among server, mobile, embeded and IoT devices',

tools/train.py

@@ -52,7 +52,10 @@ def main(config, device, logger, vdl_writer):
     train_dataloader = build_dataloader(config, 'Train', device, logger)
     if len(train_dataloader) == 0:
         logger.error(
-            'No Images in train dataset, please check annotation file and path in the configuration file'
+            "No Images in train dataset, please ensure\n" +
+            "\t1. The images num in the train label_file_list should be larger than or equal with batch size.\n"
+            +
+            "\t2. The annotation file and path in the configuration file are provided normally."
         )
         return