to_grayscale — Torchvision 0.22 documentation (original) (raw)

torchvision.transforms.functional.to_grayscale(img, num_output_channels=1)[source]¶

Convert PIL image of any mode (RGB, HSV, LAB, etc) to grayscale version of image. This transform does not support torch Tensor.

Parameters:

• img (PIL Image) – PIL Image to be converted to grayscale.
• num_output_channels (int) – number of channels of the output image. Value can be 1 or 3. Default is 1.

Returns:

Grayscale version of the image.

• if num_output_channels = 1 : returned image is single channel
• if num_output_channels = 3 : returned image is 3 channel with r = g = b

Return type:

PIL Image

Examples using to_grayscale: