hardcoded exiftool parameters

[Eric Ball]

The current version of Hugin invokes exiftool with the following hardcoded parameters (see also 696636):

exiftool -E -overwrite_original_in_place -TagsFromFile source.jpg -ImageDescription -Make -Model -Artist -WhitePoint -Copyright -GPS:all -DateTimeOriginal -CreateDate -UserComment -ColorSpace -OwnerName -SerialNumber -Software="Hugin version" -UserComment="projection info" -f panorama.jpg

The problem with this is it does not specify the tag group (e.g. EXIF or XMP) which may lead to unpredictable results, especially for photo which have been pre-processed before stiching.

A better solution would be to allow the user to specify the exiftool parameters using a Preferences panel, as is currently used for Control Point Detectors. This would also allow users to customize what metadata they want to copy from the original photos (e.g. MakerNotes) and specify metadata (e.g. Copyright).

[tmodes (tmodes)]

Some points to consider:
* Some parameters (e.g. -WhitePoint -ColorSpace) are required to get a correct output from Hugin.
* Some parameters (e.g. -Software and -UserComment) depend on other switches (-E in this case).
So there needs to be some advanced checking of the parameter so it does not break existing functionality.

According to Exiftool manual the information should be added first to Exif group (because all tags are in this group). So this should not result in unpredictable results.

[Eric Ball (eric-l-ball)]

As exiftool is used to modify the final output, there's no requirement to retain WhitePoint & ColorSpace. In my experience exiftool is also very good at handling bad input parameters (usually by ignoring them), so parameter checking is not required.

The point is, for those who wish to use exiftool to perform more (or less) than the current code there is no way to modify the hard coded parameters without recompiling.

[tmodes (tmodes)]

Implemented in changeset e34c5b4cf79 a version which uses exiftool argfiles. The user can specify its own argfile. For the syntax of the argfiles see the exiftool manual.