mmdetection/docs/en/advanced_guides/customize_transforms.md

Customize Data Pipelines

1. Write a new transform in a file, e.g., in my_pipeline.py. It takes a dict as input and returns a dict.

   import random
   from mmcv.transforms import BaseTransform
   from mmdet.registry import TRANSFORMS
   
   
   @TRANSFORMS.register_module()
   class MyTransform(BaseTransform):
      """Add your transform
   
      Args:
          p (float): Probability of shifts. Default 0.5.
      """
   
      def __init__(self, prob=0.5):
          self.prob = prob
   
      def transform(self, results):
          if random.random() > self.prob:
              results['dummy'] = True
          return results
   

2. Import and use the pipeline in your config file. Make sure the import is relative to where your train script is located.

   custom_imports = dict(imports=['path.to.my_pipeline'], allow_failed_imports=False)
   
   train_pipeline = [
      dict(type='LoadImageFromFile'),
      dict(type='LoadAnnotations', with_bbox=True),
      dict(type='Resize', scale=(1333, 800), keep_ratio=True),
      dict(type='RandomFlip', prob=0.5),
      dict(type='MyTransform', prob=0.2),
      dict(type='PackDetInputs')
   ]
   

3. Visualize the output of your transforms pipeline

To visualize the output of your transforms pipeline, tools/misc/browse_dataset.py can help the user to browse a detection dataset (both images and bounding box annotations) visually, or save the image to a designated directory. More details can refer to visualization documentation