allow physical resolution metadata to be changed in tiff metadata #2808
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
|
Looks ok, but need to figure out the new failing test now |
|
A minor snag is, that although these should be allowed to be changed, it might not be allowed to remove them if they're already there... For example, they are mandatory in the TIFF/EP spec (e.g. DNGs), but optional in Exif. |
|
@kmilos interesting! What do you recommend? Would it be possible to make the field editable but not removable? |
That would be ideal, but no ideas yet on how to get there... |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
This addresses my problem in #2794
Tiff files should be allowed to adjust the Exif.Image.XResolution, Exif.Image.YResolution, and the Exif.Image.ResolutionUnit fields just like it can be done with JP2 files.
These metadata fields are for provenance purposes only and describes the physical capabilities of how an image was captured. They have no affect on the way the image is displayed digitally by software.
We use these fields in digital archiving to capture the provenance of the dots-per-inch use by the scanner when we scanned a photo or a fragile page of a rare book. Unfortunately, the scanning pipeline will sometimes strip out these fields and they will have to be manually added back in. Right now, exiv2 can modify these fields in JP2 files but not tiff files. However, the code is modified as it is in this PR, it can do both.