This patch improve the string read/write in case of non ASCII encoding.
- When reading, checks for UTF-8 text even on ASCII data type. If it fails, Latin1 converter is used.
- When writing using V3 specs, a better check is done to identify 7-bit ASCII text.
Related to MR !358
Fixes type mismatch on 32-bit architectures.
/builddir/build/BUILD/kf6-kimageformats-6.13.0-build/kimageformats-6.13.0/src/imageformats/jxr.cpp: In member function ‘virtual bool JXRHandler::read(QImage*)’:
/builddir/build/BUILD/kf6-kimageformats-6.13.0-build/kimageformats-6.13.0/src/imageformats/jxr.cpp:994:88: error: no matching function for call to ‘min(qint64&, qsizetype)’
994 | std::memcpy(img.scanLine(y), ba.data() + convStrideSize * y, (std::min)(convStrideSize, img.bytesPerLine()));
| ~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
EXIF specs V3 added the UTF-8 data type. The MicroExif class now allows serializations to choose whether to support the V2 or V3 format. To maximize compatibility with old readers, even when V3 is set, the ASCII data type is used if possible.
The JXR plugin, based on TIFF V6 container, does not allow to use the V3 format (it does not recognize the UTF-8 data type) and therefore V2 has been forced. For all other plugins using MicroExif, it is now possible to save, e.g., descriptions in Japanese.
Please note that this patch is also a bugfix: when saving, version 3 was set but the strings were always saved as ASCII.
- Full rotation support on load and save.
- Improve also Windows compatibility by converting RGB32 to BGR32 on saving
Images saved with orientation are displayed correctly by Windows Explorer (which natively supports JXR files):
{width=597 height=259}
Improved metadata support via EXIF metadata. Since JXR is based on a TIFF container, EXIF data is read directly from the file so it always works (even with versions of libjxr that don't have the metadata reading API).
It also solves the following issues:
- Incorrect date format on saved JXR files (was saved in ISO format instead of `yyyy:MM:dd HH:mm:ss`).
- Incorrect date type setting in EXIF data: the `DateTime` tag should be updated on every save (verified by GIMP and Photoshop). Our `CreationDate` metadata is the equivalent of the EXIF `DateTimeOriginal` tag.
Closes#22
Allow to load/save info about:
- GPS info (latitude, longitude, altitude)
- Various text info (title, description, author, copyright, etc...)
- Image resolution
The compatibility of the modifications has been tested with GIMP.
