# nvidia.dali.fn.transforms.shear¶

nvidia.dali.fn.transforms.shear(*inputs, **kwargs)

Produces a shear affine transform matrix.

If another transform matrix is passed as an input, the operator applies the shear mapping to the matrix provided.

Note

The output of this operator can be fed directly to CoordTransform and WarpAffine operators.

This operator allows sequence inputs.

Supported backends
• ‘cpu’

Parameters

input (TensorList, optional) – Input to the operator.

Keyword Arguments
• angles (float or list of float or TensorList of float, optional) –

The shear angles, in degrees.

This argument is mutually exclusive with shear.

For 2D, angles contains two elements: angle_x, angle_y.

For 3D, angles contains six elements: angle_xy, angle_xz, angle_yx, angle_yz, angle_zx, angle_zy.

A shear angle is translated to a shear factor as follows:

shear_factor = tan(deg2rad(shear_angle))


Note

The valid range of values is between -90 and 90 degrees. This argument is mutually exclusive with shear. If provided, the number of dimensions of the transform is inferred from this argument.

Supports per-frame inputs.

• bytes_per_sample_hint (int or list of int, optional, default = [0]) –

Output size hint, in bytes per sample.

If specified, the operator’s outputs residing in GPU or page-locked host memory will be preallocated to accommodate a batch of samples of this size.

• center (float or list of float or TensorList of float, optional) –

The center of the shear operation.

If provided, the number of elements should match the dimensionality of the transform.

Supports per-frame inputs.

• preserve (bool, optional, default = False) – Prevents the operator from being removed from the graph even if its outputs are not used.

• reverse_order (bool, optional, default = False) –

Determines the order when combining affine transforms.

If set to False (default), the operator’s affine transform will be applied to the input transform. If set to True, the input transform will be applied to the operator’s transform.

If there’s no input, this argument is ignored.

• seed (int, optional, default = -1) –

Random seed.

If not provided, it will be populated based on the global seed of the pipeline.

• shear (float or list of float or TensorList of float, optional) –

The shear factors.

For 2D, shear contains two elements: shear_x, shear_y.

For 3D, shear contains six elements: shear_xy, shear_xz, shear_yx, shear_yz, shear_zx, shear_zy.

A shear factor value can be interpreted as the offset to be applied in the first axis when moving in the direction of the second axis.

Note

This argument is mutually exclusive with angles. If provided, the number of dimensions of the transform is inferred from this argument.

Supports per-frame inputs.