Some code cleanup.
Added new package with classes Slide and TiledImage to add a layer of
abstraction above TIFFImage class to make it easier to access thumbnail,
label and pyramid level images.
Added a new package and classes to support creating JSON metadata for a
TIFF slide file. Updated App to print this JSON metadat when given the -m
option.
Created abstract class SlideDataFactory with one sub-class:
PhilipsSlideDataFactory. Currently this class only returns SlideMetadata
and does not return a Slide. Deleted unneeded classes TIFFMetadataFactory
and PhilipsMetadataFactory.
Fleshed out the implementation of PhilipsSlideDataFactory.
Deleted unnecessary class TiledImageData.