uploading cropping scripts

Author: JudasDie

lib/tutorial/Ocean/ocean.md

@@ -61,7 +61,8 @@ python tracking/test_ocean.py --arch Ocean --resume snapshot/OceanV.pth --datase
 :cloud::cloud::cloud::cloud::cloud::cloud::cloud::cloud::cloud::cloud::cloud::cloud::cloud::cloud::cloud::cloud::cloud::cloud::cloud::cloud::cloud::cloud::cloud::cloud::cloud::cloud::cloud::cloud::cloud::cloud::cloud::cloud::cloud:
 ## Training
 #### prepare data
-Please download training data from [here](https://drive.google.com/drive/folders/1ehjVhg6ewdWSWt709zd1TkjWF7UJlQlq?usp=sharing), and then put them in `$TracKit/data`
+- Please download training data from [here](https://drive.google.com/drive/folders/1ehjVhg6ewdWSWt709zd1TkjWF7UJlQlq?usp=sharing), and then put them in `$TracKit/data`
+- You could also refer to scripts in `$TracKit/lib/dataset/crop` to process your custom data. 
 
 #### prepare pretrained model
 Please download the pretrained model on ImageNet [here](https://drive.google.com/open?id=1Pwe5NRdOoGiTYlnrOZdL-3S494RkbPQe), and then put it in `$TracKit/pretrain`.