Not all metadata copied

[Martijn]

Not all metadata is properly copied from the first image (or middle, or average, or whatever).

Namely the fields that describe the lens, ISO rating, metering mode, flash, exposure program, exposure comp, country code, country, province, city, location, label, rating, keywords, copyright.

That's as far as I could find. I suspect a couple more fields are missing, but I haven't tested all of them. I suppose this is enough of an indication that, although the "copy metadata" checkbox in Preferences is ticked, it 'forgets' to copy a boatload of fields.

Some metadata is copied though, like author, camera, gps, but nothing more as fas as I can tell quickly enough.

I can see there's two more boxes in Preferences for "argfiles", but I have no idea what I should put there, and I have no way of knowing what it expects me to do there. Or if it's going to help me in the first place. At any rate, I would say just simply copy ALL metadata. If it's using exiftool, copying ALL metadata should be a lot easier than copying an arbitrary set.

In the mean time, is there a trivial workaround that we can apply?

This is Hugin 2015.0.0 on Windows 10 x64.

[Martijn (m3rtijn)]

This command should work fine, to copy all metadata from the first image to the pano:

```
exiftool -TagsFromFile image-0001.tiff "-all:all>all:all" pano.tiff
```

[tmodes (tmodes)]

That's not a bug, it's a feature.
After stitching the original metadata does not apply to the final image any more. E.g. focal length, field of view and exposure time are different from the input image.
Copying all would also copy an existing thumbnail which is incorrect for the stitched image.
Therefore by default we copy only a subset of the metadata which are also valid for the stitched image.

So this will not change in the code base.

But we provide a way for the user to select for him itself, which metadata to copy. This can be done with exiftool argfiles (see exiftool manual for details about these argfiles, switch -@).
There are 2 different argfiles
1.) An intermediate argfile: this is used when copying metadata to intermediates images (remapped images, fused stacks, blended exposure layers). This is internal used like "exiftool -tagsfromfile source.jpg -@ intermediate_argfile destination.jpg"
2.) A final argfile: this is additional used for the final panorama. This argfile is used additional to the intermediate argfile: "exiftool -tagsfromfile source.jpg -@ intermediate_argfile -@ final_argfile destination.jpg"
In the final argfile there will additionally some place holders replaced.

For more details about the exiftool argfile, read the exiftool manual.

[Martijn (m3rtijn)]

Metadata like lens information and exposure information CAN be copied if it remains the same accross all pictures (this is likely to be case, in a well-shot panorama). Same goes for other metadata like rating and label.

So please reconsider.

Metadata that would be correct in, say, 80% of cases is better than no metadata ever.

[Martijn (m3rtijn)]

Or, first apply ALL metadata from the first/middle/last image, and then reapply metadata that has changed, like the thumbnail.

More generally speaking I suppose, copying metadata needs to be smarter.

[tmodes (tmodes)]

> Metadata like lens information and exposure information
> CAN be copied if it remains the same accross all pictures
> (this is likely to be case, in a well-shot panorama).

This is wrong:
1. After stitching with Hugin the projection and also the field of view (and therefore the focallength) changes and therefore the lensinformation becomes invalid.
2. Hugin can also work with images with different field of view. So your assumption is not valid.
3. Hugin can also work with images from different lenses or even from different cameras.
4. During stitching Hugin applies photometric correction and you can select the output exposure value. So the exposure value from the input image is not valid for the final image.

[Martijn (m3rtijn)]

1. But the lens information that CAN be copied, should be. Like lens make & model. I would actually say the focal length does remain the same, since the focal length says something about the physicalities of the lens, not neccesarily about the picture. Think digital zoomin, cropping, and other digital corrections. Apterture also doesn't change.
2. Which is why I said "if it [the metadata] remains the same accross all pictures".
3. In such case, don't copy things that aren't the same.
4. Yes it is. Exposure says something about the shot, not about the final image. If you do exposure corrections in Lightroom, it also doesn't change the exposure metadata, which in my mind, is correct.