Set Metadata inconsistent results

As far as I can tell this should be considered a bug, but please inform me if otherwise.

Issues outlined here seem somewhat related to those I spelled out in this thread I started two years ago. Using Dopus v12.20 now, in Windows 10 Pro 1903 x64. I’m basically continuing experiments with metadata using DOpus and ExifTool. As in the older thread linked to above, I started out with a fresh, blank 1-bit PNG with no metadata, created in PaintShop Pro, then manually added a number of metadata fields via DOpus, then used ExifTool to export all EXIF/IPTC/XMP fields to JSON to see where the information I added via DOpus actually went. The DOpus Set Metadata fields I added in this case were:

Authors: <authors>
Copyright: <copyright>
Description: <description>
Instructions: <instructions>
Subject: <subject>
Title: <title>
Camera make: <camera make>
Camera model: <camera model>
Creation software: <creation software>
Date digitized: 11:59:59 31-Dec-2019
Date taken: 00:00:00 01-Jan-1900
GPS Altitude: 1
GPS Latitude: 2 3 4 N
GPS Longitude: 5 6 7 W
Lens make: <lens make>
Lens model: <lens model>
Rotation: 0
Comment: <comment>
Tags: <tags>; <tag1>; <tag2>; <tag3>; <tag4>

In all cases that I know of, when I’ve added and applied content to all these fields, the date I entered into Date taken was added to XMP:DateTimeOriginal, EXIF:DateTimeOriginal and IPTC:DateCreated, and the date I entered into Date digitized was added to XMP:CreateDate and EXIF:CreateDate. At one point today, I only added Date taken and Date digitized via DOpus Set Metadata, which resulted in only the EXIF date/time fields being added. Subsequently adding all the other fields as listed above did not result in the XMP:DateTimeOriginal and IPTC:DateCreated fields finally being added, though modifying both dates/time fields in Set metadata did. I’ve been able to reproduce this with the same blank starting PNG, and with several other PNGs. Any idea what’s up?

Also, I was trying to use ExifTool to modify the existing content of IPTC:DateCreated and XMP:UserComment, as originally set via DOpus, but got errors. Upon further research and inquiries made at the ExifTool help forum, I learned that the official IPTC specification limits IPTC:DateCreated to date only, while separately specified field IPTC:TimeCreated is intended for the time component. Similarly, the official XMP specification defines XMP:UserComment as a lang-alt-list, rather than a straight text string as DOpus apparently writes it. Because of these, I’m unable to use ExifTool to modify the existing content, or to write new content in the existing format.

Please let me know if it would be useful for me to upload the wayward PNG, and/or maybe the pre-metadata version of it, if you can’t reproduce these results independently.

We don't add IPTC fields unless some are already there.

Please zip and upload the PNG so we can take a look at it.

As I see it, if that’s true, then ExifTool is erroneously confirming the complete absence of metadata prior to my adding it via DOpus, and/or erroneously reporting the IPTC fields present following my DOpus procedures, which would boggle my mind, but I’ll happily take that up with Phil Harvey if you’re firm on it. Let me know.

See attached: “2020-06-14-MAZE-DOpus-ExifTool-Test.7z” (2,745)

Contents:

“2020-06-14-MAZE-DOpus-ExifTool-Test\”
“20200531170000 [BLANK].png” (5,226) [1000 x 1000 x 24]
“20200531170000.png” (9,183) [1000 x 1000 x 24]
“20200531170000 [2].png” (9,144) [1000 x 1000 x 24]
“20200531170000 [2].png.1.json” (148)
“20200531170000 [2].png.2.json” (1,202)
“20200531170000 [2].png.3.json” (1,342)

2020-06-14-MAZE-DOpus-ExifTool-Test.7z (2.7 KB)

Thanks for the files!

It looks like setting any of Instructions, Title, or Tags will result in XMP data being added to the file. I'm assuming this is because the tagging library we use doesn't have a way to store those as EXIF, although I'm not 100% sure yet.

As a check, if you avoid (or clear) those three fields, do you still get problems?

And IPTC, unless you’re still firm on DOpus not being the culprit for that, but I can’t imagine what else could be adding it.

I guess it depends on what you think of as problems. XMP and IPTC do get added for Instructions, Title, or Tags, and they also get added for Date digitized (EXIF/XMP) and Date taken (EXIF/XMP/IPTC), IF Instructions, Title, or Tags were added in the same operation. If all of the above-mentioned fields have been added via DOpus, subsequently deleting Instructions, Title, and/or Tags via DOpus results in the corresponding EXIF/XMP/IPTC for those fields going away, but not any of the varieties for Date digitized or Date taken.

I don’t have a particular problem with XMP and IPTC being added, but I do wish DOpus was consistent about, and that the official specifications were obeyed.

Another 7-zip file uploaded with PNGs and JSONs from the most recent round of experimentation, in case they’re useful. The filenames hopefully explain what operation took place for each pair.

Attached: “2020-06-15-MAZE-NoMeta-Meta Test.7z” (2,355)

Contents:

“2020-06-15-MAZE-NoMeta-Meta Test\”
“1-NoMeta.png” (640) [1000 x 1000 x 1]
“1-NoMeta.png.json” (1,043)
“2-DateTimeOnly.png” (786) [1000 x 1000 x 1]
“2-DateTimeOnly.png.json” (144)
“3-InstructionsTitleTagsDateTime.png” (3,873) [1000 x 1000 x 1]
“3-InstructionsTitleTagsDateTime.png.json” (598)
“4-InstructionsTitleTagsOnly.png” (3,567) [1000 x 1000 x 1]
“4-InstructionsTitleTagsOnly.png.json” (384)
“5-InstructionsTitleTagsDateTime-InstTitleTags.png” (3,408) [1000 x 1000 x 1]
“5-InstructionsTitleTagsDateTime-InstTitleTags.png.json” (354)