Hello,
I'm trying to see if I can update the comment and date created portions in a PNG iTxt chunk. Please see extracted portion below:
PNG iTXt (495 bytes):
+ [XMP directory, 473 bytes]
| XMPToolkit = XMP Core 5.4.0
| UserComment = Screenshot
| DateCreated = 2020-09-21T21:32:01
Questions:
1 - it seems like iTXt chunks are writable looking at the documentation http://web.mit.edu/jhawk/mnt/cgs/Image-ExifTool-6.99/html/TagNames/PNG.html#TextualData (http://web.mit.edu/jhawk/mnt/cgs/Image-ExifTool-6.99/html/TagNames/PNG.html#TextualData) - but I'm struggling to find out how I can get ExifTool to update the chunk with XMP tags since the format is not listed.
2 - I would also like to know if I can inject the iTxt XMP tags above into PNG files which do not have embedded already.
Thanks,
- Borna
You're overthinking it. Just set the XMP tags and exiftool will take care of the details. An example using the data in your listing
exiftool -XMPToolkit="XMP Core 5.4.0" -XMP:UserComment=Screenshot -XMP:DateCreated=2020-09-21T21:32:01 FILE.PNG
ahh crap! I thought that the PNG chunks were data blobs that needed special handling like the ICC headers.
Thanks it is working.
- Borna