* #584: Implemented missing member function
* API change, class PreviewImage: Added members to access all preview properties
* Minor fix: Suppress XMP encoding error when XMP is not enabled.
- Refactoring code: main loop to parse PNG chunk contents go to pngimage class. pngchunk only play with chunk contents
- Implement PNG writting mode : all metadata are supported:
* UTF8 comment as "Description" iTXt chunk (compressed)
* XMP data as iTXt chunk (uncompressed as XMP spec instruction)
* IPTC data as zTXt chunk (compressed and encoded as ImageMagick method)
* EXIF data as zTXt chunk (compressed and encoded as ImageMagick method)
Note: writting mode resample metadata chunk to follow list given behind. There are several ways where other programs writte metadata in other place.
For ex : digiKam 0.9.x or ImageMagick 5.x writte Exif and Iptc to an tEXt chunk (uncompressed)
ImageMagick 5.x writte Xmp to an uncompressed tEXt chunk
ImageMagick 6.x writte Xmp to a compressed zTXt chunk.
Andreas Huggel
HumanDynamo