def saturation_jitter(var, images):
    """
    Perfrom saturation jittering on the input images. The channels of images
    should be in order BGR.
    Args:
        var (float): jitter ratio for saturation.
        images (tensor): images to perform color jitter. Dimension is
            `num frames` x `channel` x `height` x `width`.
    Returns:
        images (tensor): the jittered images, the dimension is
            `num frames` x `channel` x `height` x `width`.
    """
    alpha = 1.0 + np.random.uniform(-var, var)
    img_gray = grayscale(images)
    images = blend(images, img_gray, alpha)

    return images
Perfrom saturation jittering on the input images. The channels of images
should be in order BGR.
Args:
var (float): jitter ratio for saturation.
images (tensor): images to perform color jitter. Dimension is
`num frames` x `channel` x `height` x `width`.
Returns:
images (tensor): the jittered images, the dimension is
`num frames` x `channel` x `height` x `width`.
videomamba/video_sm/datasets/video_transforms.py