Print Page - Writing exif tags on PNG images

Title: Writing exif tags on PNG images
Post by: Alyssa on February 02, 2015, 12:15:12 PM

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.

Title: Re: Writing exif tags on PNG images
Post by: Phil Harvey on February 02, 2015, 12:24:59 PM

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

- Phil

Title: Re: Writing exif tags on PNG images
Post by: Alyssa on February 02, 2015, 01:49:13 PM

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)

(https://lh4.googleusercontent.com/-h3x5f_Cpj-Q/VM_GOUgryvI/AAAAAAACbqw/z8hGE-PJM40/w1913-h995-no/Senza%2Btitolo%2B-%2B2.png)

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

Title: Re: Writing exif tags on PNG images
Post by: Phil Harvey on February 02, 2015, 01:54:09 PM

FAQs number 10 and 18 (https://exiftool.org/faq.html#Q10) help with this problem.

- Phil

Title: Re: Writing exif tags on PNG images
Post by: Alyssa on February 02, 2015, 02:26:59 PM

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.

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ExifTool => Newbies => Topic started by: Alyssa on February 02, 2015, 12:15:12 PM