grayscale_with_type_alpha

image::imageops::colorops

Function grayscale_with_type_alpha 

Source 
pub fn grayscale_with_type_alpha<NewPixel, I: GenericImageView>(
    image: &I,
) -> ImageBuffer<NewPixel, Vec<NewPixel::Subpixel>>
where
    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.