@Override
    public String toString() {
        return toString(null);
    }
Returns the size of the first JPEG thumbnail found in the EXIF metadata.

@return Thumbnail width and height or null if no thumbnail.
@throws ImagingException if it fails to read the image
@throws IOException      if it fails to read the image size
src/main/java/org/apache/commons/imaging/formats/jpeg/JpegImageMetadata.java