Windows11 (25H2), display resolution 3840x2160, dpi scale 150%
EXIF - encoding - standard text tags
XnViewMP uses Type 2 when writing UTF-8 data to EXIF standard text tags.
This is common practice in the real world under EXIF 2.x, but it is not compliant with the EXIF 3.0 specification, which introduced the new Type 129 for UTF-8 text. report from KUSO EXIF Viewer for exif_written_by_XnViewMP.jpg from this post
Suggestion
- maybe add an option to select Type (2 [02 00] or 129 [81 00]) when writing UTF-8 text to standard text tags
to clearly indicate that byte payload contains UTF-8 text
I would not use only Type 129, as there are not many apps that support it, if any.
ref
| Field Group | EXIF 2.x Specification | EXIF 3.0 Specification | Extended / Legacy Practice |
|---|---|---|---|
| Standard Text Tags (Artist, Copyright, ImageDescription, Software, etc.) | Strictly 7-bit ASCII (Type 2). Multi-byte characters explicitly forbidden. | Formally updated to ASCII or UTF-8 (Type 129). Native multi-byte support. | Raw UTF-8 was widely injected informally by modern tools prior to EXIF 3.0. |
| Header-Encoded Tags (UserComment, GPSProcessingMethod, etc.) | UNDEFINED (Type 7). Uses 8-byte header prefix (Unicode\0 for UTF-16, JIS\0, ASCII\0). | Header mechanism retained for backward compatibility. | Was the only official way to store international text in EXIF 2.x. |
| Windows XP Tags (XPKeywords, XPTitle, XPComment, etc.) | BYTE (Type 1). Proprietary Microsoft extension using UTF-16LE / UCS-2. | Not part of core EXIF spec (Microsoft proprietary extension). | Native UTF-16LE support across Windows OS and file properties. |