resize

torchvision.transforms.functional.resize(img: Tensor, size: List[int], interpolation: InterpolationMode = InterpolationMode.BILINEAR, max_size: Optional[int] = None, antialias: Optional[bool] = None) → Tensor

Resize the input image to the given size. If the image is torch Tensor, it is expected to have […, H, W] shape, where … means an arbitrary number of leading dimensions

Warning

The output image might be different depending on its type: when downsampling, the interpolation of PIL images and tensors is slightly different, because PIL applies antialiasing. This may lead to significant differences in the performance of a network. Therefore, it is preferable to train and serve a model with the same input types. See also below the antialias parameter, which can help making the output of PIL images and tensors closer.

Parameters:

• img (PIL Image or Tensor) – Image to be resized.

• size (sequence or int) –

  Desired output size. If size is a sequence like (h, w), the output size will be matched to this. If size is an int, the smaller edge of the image will be matched to this number maintaining the aspect ratio. i.e, if height > width, then image will be rescaled to \(\left(\text{size} \times \frac{\text{height}}{\text{width}}, \text{size}\right)\).

  Note

  In torchscript mode size as single int is not supported, use a sequence of length 1: [size, ].

• interpolation (InterpolationMode) – Desired interpolation enum defined by torchvision.transforms.InterpolationMode. Default is InterpolationMode.BILINEAR. If input is Tensor, only InterpolationMode.NEAREST, InterpolationMode.BILINEAR and InterpolationMode.BICUBIC are supported. For backward compatibility integer values (e.g. PIL.Image[.Resampling].NEAREST) are still accepted, but deprecated since 0.13 and will be removed in 0.15. Please use InterpolationMode enum.

• max_size (int, optional) – The maximum allowed for the longer edge of the resized image: if the longer edge of the image is greater than max_size after being resized according to size, then the image is resized again so that the longer edge is equal to max_size. As a result, size might be overruled, i.e the smaller edge may be shorter than size. This is only supported if size is an int (or a sequence of length 1 in torchscript mode).

• antialias (bool, optional) – antialias flag. If img is PIL Image, the flag is ignored and anti-alias is always used. If img is Tensor, the flag is False by default and can be set to True for InterpolationMode.BILINEAR and InterpolationMode.BICUBIC modes. This can help making the output for PIL images and tensors closer.

Returns:

Resized image.

Return type:

PIL Image or Tensor

Examples using resize:

Optical Flow: Predicting movement with the RAFT model

Optical Flow: Predicting movement with the RAFT model

Illustration of transforms

Illustration of transforms