Today, ImageMetadataReader will throw an ImageProcessingException() for
unspported file format (using throw new ImageProcessingException("File format
is not supported")).
It would be helpful if we could catch this error specifically, since we want
different error handling for this compared to other (unknown errors)
The simplest (and probably also best :-)) way would be to create a subclass
"UnsupportedFileFormatException" and throw that instead.