Function resize
fn resize<I: GenericImageView>(image: &I, nwidth: u32, nheight: u32, filter: FilterType) -> ImageBuffer<<I as >::Pixel, Vec<<<I as >::Pixel as Pixel>::Subpixel>>
where
<I as >::Pixel: 'static,
<<I as >::Pixel as Pixel>::Subpixel: 'static
Resize the supplied image to the specified dimensions.
nwidth and nheight are the new dimensions.
filter is the sampling filter to use.