Function otsu_threshold_u8 

pub fn otsu_threshold_u8(
    input: ImageView<'_, u8, 1>,
    max_value: u8,
    threshold_type: ThresholdType,
) -> Result<(u8, Image<u8, 1>), VisionError>

Selects an Otsu threshold for an 8-bit grayscale image and applies it.