- Separate package for the resources (seems to be a lot)?
  - Move to metadata package, or implement metadata interface, as this is (similar|equivalent) to TIFF/JPEG APP13 segment tag?
- Possibility to read only some resources? readResources(int[] resourceKeys)?
  - Probably faster when we only need the color space
- Support for Photoshop specific TIFF tags (extension for TIFFImageReader)?
- PSDImageWriter?
