tca_correct fails with "expecting exactly one alpha band"

[Torsten Bronger]

Since revision 7033:5f45958ae420, tca_correct fails on my TIFFs with the following output:

$ tca_correct -o v tca_issue.tiff
...
ERROR: caught exception:
Precondition violation!
vigra::detail::read_image_bands_and_alpha: expecting exactly one alpha band
(/home/user/hugin/src/hugin_base/vigra_ext/impexalpha.hxx:113)

[Torsten Bronger (bronger)]

My TIFF can be downloaded here: https://bob.ipv.kfa-juelich.de/bronger/tca_issue.tiff.xz
(74 MB)

[tduell (tduell-iinet)]

I tried your file with hugin-7200:d185664c5ce1, and got this message...

Warning: no TIFFTAG_SAMPLEFORMAT or TIFFTAG_DATATYPE, guessing pixeltype 'UINT16'.
Warning: no TIFFTAG_SAMPLEFORMAT or TIFFTAG_DATATYPE, guessing pixeltype 'UINT16'.
Warning: no TIFFTAG_SAMPLEFORMAT or TIFFTAG_DATATYPE, guessing pixeltype 'UINT16'.
ERROR: caught exception:
Precondition violation!
vigra::detail::read_image_bands_and_alpha: expecting exactly one alpha band
(/home/terry/rpmbuild/BUILD/hugin-2015.1.0/src/hugin_base/vigra_ext/impexalpha.hxx:119)

I then loaded your image into Darktable, and exported as tif tried again, and got this message...

[terry@localhost Torsten]$ tca_correct -o v tca_issue_DT.tif
ERROR: caught exception:
Precondition violation!
vigra::detail::read_image_bands_and_alpha: expecting exactly one alpha band
(/home/terry/rpmbuild/BUILD/hugin-2015.1.0/src/hugin_base/vigra_ext/impexalpha.hxx:119)

so looks like the issue can be reproduced.

Cheers,
Terry

[tmodes (tmodes)]

Fixed in changeset c86f9b1d8c1c0d13a3e93574743ca965df17175d

PS: Next time please try if you can reproduce the issue with a smaller file and attach this smaller file.