pub fn grayscale_with_type_alpha<NewPixel, I>(
image: &I,
) -> ImageBuffer<NewPixel, Vec<<NewPixel as Pixel>::Subpixel>>where
I: GenericImageView,
NewPixel: Pixel + FromColor<LumaA<<<I as GenericImageView>::Pixel as Pixel>::Subpixel>>,Expand description
Convert the supplied image to a grayscale image with the specified pixel type. Alpha channel is preserved.