mindspore.dataset.vision.c_transforms.RandomAffine

class mindspore.dataset.vision.c_transforms.RandomAffine(degrees, translate=None, scale=None, shear=None, resample=Inter.NEAREST, fill_value=0)

Apply Random affine transformation to the input image.

Parameters

• degrees (Union[int, float, sequence]) – Range of the rotation degrees. If degrees is a number, the range will be (-degrees, degrees). If degrees is a sequence, it should be (min, max).

• translate (sequence, optional) – Sequence (tx_min, tx_max, ty_min, ty_max) of minimum/maximum translation in x(horizontal) and y(vertical) directions, range [-1.0, 1.0] (default=None). The horizontal and vertical shift is selected randomly from the range: (tx_min*width, tx_max*width) and (ty_min*height, ty_max*height), respectively. If a tuple or list of size 2, then a translate parallel to the X axis in the range of (translate[0], translate[1]) is applied. If a tuple or list of size 4, then a translate parallel to the X axis in the range of (translate[0], translate[1]) and a translate parallel to the Y axis in the range of (translate[2], translate[3]) are applied. If None, no translation is applied.

• scale (sequence, optional) – Scaling factor interval, which must be non negative (default=None, original scale is used).

• shear (Union[int, float, sequence], optional) – Range of shear factor, which must be positive (default=None). If a number, then a shear parallel to the X axis in the range of (-shear, +shear) is applied. If a tuple or list of size 2, then a shear parallel to the X axis in the range of (shear[0], shear[1]) is applied. If a tuple or list of size 4, then a shear parallel to X axis in the range of (shear[0], shear[1]) and a shear parallel to Y axis in the range of (shear[2], shear[3]) is applied. If None, no shear is applied.

• resample (Inter, optional) –

  An optional resampling filter (default=Inter.NEAREST). It can be any of [Inter.BILINEAR, Inter.NEAREST, Inter.BICUBIC].

  • Inter.BILINEAR, means resample method is bilinear interpolation.

  • Inter.NEAREST, means resample method is nearest-neighbor interpolation.

  • Inter.BICUBIC, means resample method is bicubic interpolation.

• fill_value (Union[int, tuple[int]], optional) – Optional fill_value to fill the area outside the transform in the output image. There must be three elements in tuple and the value of single element is [0, 255]. (default=0, filling is performed).

Raises

• TypeError – If degrees is not of type int, float or sequence.

• TypeError – If translate is not of type sequence.

• TypeError – If scale is not of type sequence.

• TypeError – If shear is not of type int, float or sequence.

• TypeError – If resample is not of type mindspore.dataset.vision.Inter.

• TypeError – If fill_value is not of type int or tuple[int].

• ValueError – If degrees is negative.

• ValueError – If translate is not in range [-1.0, 1.0].

• ValueError – If scale is negative.

• ValueError – If shear is not positive.

• RuntimeError – If given tensor shape is not <H, W> or <H, W, C>.

Supported Platforms:

CPU

Examples

>>> from mindspore.dataset.vision import Inter
>>> decode_op = c_vision.Decode()
>>> random_affine_op = c_vision.RandomAffine(degrees=15,
...                                          translate=(-0.1, 0.1, 0, 0),
...                                          scale=(0.9, 1.1),
...                                          resample=Inter.NEAREST)
>>> transforms_list = [decode_op, random_affine_op]
>>> image_folder_dataset = image_folder_dataset.map(operations=transforms_list,
...                                                 input_columns=["image"])