A limitation of the existing design is that there is no way to obtain
an IIOMetadataFormat object without either reading an image or having
access to an encoder for a format. An application might wish to
retrieve such an object without performing actual decoding. This may
be remedied by providing accessor methods in the ImageReaderWriterSpi
class, which is meant to provide information about reader and writer
plug-ins without instantiating actual readers or writers.