adapt mri mask to image size

factories.py

@@ -194,6 +194,10 @@ class PhysicsWithGenerator(torch.nn.Module):
             use_gen = True
 
         if use_gen:
+            if self.name == 'MRI':  # RandomMaskGenerator deoends on image size
+                _, _, h, w = x.shape
+                self.generator = dinv.physics.generator.RandomMaskGenerator((2, h, w), acceleration_factor=4)
+
             kwargs = self.generator.step(batch_size=x.shape[0])  # generate a set of params for each sample
             self.update_saved_params_and_physics(**kwargs)