nvidia.dali.fn.color_twist

nvidia.dali.fn.color_twist(__input, /, *, brightness=1.0, bytes_per_sample_hint=[0], contrast=1.0, dtype=None, hue=0.0, image_type=DALIImageType.RGB, preserve=False, saturation=1.0, seed=-1, device=None, name=None)

Adjusts hue, saturation, brightness and contrast of the image.

This operator allows sequence inputs and supports volumetric data.

Supported backends

• ‘cpu’

• ‘gpu’

Parameters:

__input (TensorList ('HWC', 'FHWC', 'DHWC')) – Input to the operator.

Keyword Arguments:

• brightness (float or TensorList of float, optional, default = 1.0) –

  Brightness change factor.

  Values must be non-negative.

  Example values:

  • 0 - Black image.

  • 1 - No change.

  • 2 - Increase brightness twice.

  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.

• contrast (float or TensorList of float, optional, default = 1.0) –

  Contrast change factor.

  Values must be non-negative.

  Example values:

  • 0 - Uniform grey image.

  • 1 - No change.

  • 2 - Increase brightness twice.

  Supports per-frame inputs.

• dtype (nvidia.dali.types.DALIDataType, optional) –

  Output data type.

  If not set, the input type is used.

• hue (float or TensorList of float, optional, default = 0.0) –

  Hue change, in degrees.

  Supports per-frame inputs.

• image_type (nvidia.dali.types.DALIImageType, optional, default = DALIImageType.RGB) – The color space of the input and the output image.

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

• saturation (float or TensorList of float, optional, default = 1.0) –

  Saturation change factor.

  Values must be non-negative.

  Example values:

  • 0 - Completely desaturated image.

  • 1 - No change to image’s saturation.

  Supports per-frame inputs.

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

  Random seed.

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