Use custom test-time augmentations (#201)

Author: Kaushalya

pytorch_grad_cam/base_cam.py

@@ -1,7 +1,7 @@
 import numpy as np
 import torch
 import ttach as tta
-from typing import Callable, List, Tuple
+from typing import Callable, List, Tuple, Optional
 from pytorch_grad_cam.activations_and_gradients import ActivationsAndGradients
 from pytorch_grad_cam.utils.svd_on_activations import get_2d_projection
 from pytorch_grad_cam.utils.image import scale_cam_image
@@ -15,7 +15,8 @@ def __init__(self,
                  use_cuda: bool = False,
                  reshape_transform: Callable = None,
                  compute_input_gradient: bool = False,
-                 uses_gradients: bool = True) -> None:
+                 uses_gradients: bool = True,
+                 tta_transforms: Optional[tta.Compose] = None) -> None:
         self.model = model.eval()
         self.target_layers = target_layers
         self.cuda = use_cuda
@@ -24,6 +25,16 @@ def __init__(self,
         self.reshape_transform = reshape_transform
         self.compute_input_gradient = compute_input_gradient
         self.uses_gradients = uses_gradients
+        if tta_transforms is None:
+            self.tta_transforms = tta.Compose(
+                [
+                    tta.HorizontalFlip(),
+                    tta.Multiply(factors=[0.9, 1, 1.1]),
+                ]
+            )
+        else:
+            self.tta_transforms = tta_transforms
+
         self.activations_and_grads = ActivationsAndGradients(
             self.model, target_layers, reshape_transform)
 
@@ -148,14 +159,8 @@ def forward_augmentation_smoothing(self,
                                        input_tensor: torch.Tensor,
                                        targets: List[torch.nn.Module],
                                        eigen_smooth: bool = False) -> np.ndarray:
-        transforms = tta.Compose(
-            [
-                tta.HorizontalFlip(),
-                tta.Multiply(factors=[0.9, 1, 1.1]),
-            ]
-        )
         cams = []
-        for transform in transforms:
+        for transform in self.tta_transforms:
             augmented_tensor = transform.augment_image(input_tensor)
             cam = self.forward(augmented_tensor,
                                targets,