Writing exif tags on PNG images

[Alyssa]

Hello
I've recently started to work with some transparent images, and since JPG doesn't support a transparency layer, I had to to keep em as PNG.
Problem is,I'd need to operate with at least 2 writable tags(which supports ASCII characters) where I can store the Author's name and the creation date, and tags like "subject" or "XPComment" doesn't work on PNG images...are there at least 2 tags I can use?

Thanks.

[Phil Harvey]

I suggest using XMP.  Maybe XMP-dc:Creator and XMP-xmp:CreateDate.

- Phil

[Alyssa]

Hello
Thanks for the tip, I found the tags "-XMP-dc:Creator" and "-XMP-dc:Description" the most useful, however I've ran into a problem with the charset not displaying correctly
(I used an old script to add the file create date in a personalized format)



It should normally display "Lunedì"
(The same script works fine with JPG Image's exif:XPComment tag)

[Phil Harvey]

FAQs number 10 and 18 help with this problem.

- Phil

[Alyssa]

Hi Phil
Seems like setting chcp 65001 in Windows's command prompt solved the display issue,also exporting the tag into an external .txt file shows the text correctly,I'll be make some more tests later but hopefully it should be fine as long as it just a display issue.
Thanks.

Edit:Tested a few things and everything works.