composer.algorithms.utils.augmentation_common#

composer.algorithms.utils.augmentation_common

Functions

`cast`	Cast a value to a type.
`image_as_type`	Converts between `torch.Tensor` and
`map_pillow_function`	Lifts a function that requires pillow images to also work on tensors.

Classes

`Image`	This class represents an image object.
`TypeVar`	Type variable.

Attributes

composer.algorithms.utils.augmentation_common.image_as_type(image, typ)[source]#

Converts between torch.Tensor and: PIL.Image.Image image representations

Parameters

image – a single image represented as a PIL.Image.Image or a rank 2 or rank 3 torch.Tensor in HW or CHW format. A rank 4 or higher tensor can also be provided as long as no type conversion is needed; in this case, the input tensor will be returned. This case is allowed so that functions that natively operate on batch tensors can safely call image_as_type(image, torch.Tensor) without additional error and type checking.
typ – type of the copied image. Must be PIL.Image.Image or torch.Tensor

Returns

A copy of ``image`` with type ``typ``

Raises

TypeError – if typ is not one of torch.Tensor or PIL.Image.Image
ValueError – if image cannot be converted to the typ, such as when requesting conversion of a rank 4 tensor to PIL.Image.Image.

composer.algorithms.utils.augmentation_common.map_pillow_function(f_pil, imgs)[source]#

Lifts a function that requires pillow images to also work on tensors.

Parameters

f_pil – a callable that takes maps PIL.Image.Image objects to other PIL.Image.Image objects.
imgs – a PIL.Image.Image or a torch.Tensor in HW, CHW or NCHW format.

Returns