Function image::dynimage::image_dimensions

pub fn image_dimensions<P>(path: P) -> ImageResult<(u32, u32)>
where
    P: AsRef<Path>,

Read a tuple containing the (width, height) of the image located at the specified path. This is faster than fully loading the image and then getting its dimensions.

Try io::Reader for more advanced uses, including guessing the format based on the file’s content before its path or manually supplying the format.