Function image::imageops::colorops::grayscale

pub fn grayscale<I: GenericImage>(
    image: &I
) -> ImageBuffer<Luma<<I::Pixel as Pixel>::Subpixel>, Vec<<I::Pixel as Pixel>::Subpixel>> where
    <I::Pixel as Pixel>::Subpixel: 'static,
    <<I::Pixel as Pixel>::Subpixel as Num>::FromStrRadixErr: 'static, 

Convert the supplied image to grayscale