# Hugin: fails to read png images



## sparky2002 (Dec 12, 2017)

As of last year I used Hugin to assemble panoramas without problems. My usual workflow consists of converting from raw to PNG from Darktable, setting panorama elements aside in a work directory then loading those PNG files in Hugin to assemble the panorama.

Coming back to it after a while, as of today I cannot load PNGs (nor TIFFs, it seems) as input files in Hugin: From the Assistant tab, "Load images...", select (even just one) PNG file and I get a dialog "Unsupported image format / Could not decode image: <first file of the list>, Abort."

Starting Hugin from the command line I also get the following:

```
ERROR: caught exception:
Precondition violation!
did not find a matching file type.
(/wrkdirs/usr/ports/graphics/vigra/work/vigra-e6c21f3/src/impex/codecmanager.cxx:234)

Could not get pixel type for file <first file>.png
```

I get something similar but much less verbose attempting to run pto_gen from the command line: 

```
% pto_gen <a series of .png files>
Generating pto file...
pto_gen: No valid image files given.
```

I tried removing/reinstalling Hugin from packages as well as from ports, and clearing the .hugin
 directory from $HOME; it doesn't have any effect.

Does anyone have a clue/could point me in the right direction ?
Thanks.


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## ldgc (Dec 15, 2017)

Hello sparky2002

I am not familiar with this kind of software, however after some search I saw a possible solution to a problem similar to yours.
The solution was to remove any "special" character in your path/image name - e.g. Eastern European characters.

I hope this helps solve your issue


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## sparky2002 (Dec 16, 2017)

pensador_13 said:


> Hello sparky2002
> 
> I am not familiar with this kind of software, however after some search I saw a possible solution to a problem similar to yours.
> The solution was to remove any "special" character in your path/image name - e.g. Eastern European characters.
> ...



I scoured the net and found that trick, too. Unfortunately it doesn't apply, there is no special character in the path or the filename itself.

On a related note, I spun up a VM today and did a fresh install of FreeBSD 11 inside it, from the 11.1-RELEASE ISO, with no further update; installed xorg, xfce and hugin on top of that (all from packages), and copied a few PNGs to assemble into the VM. Exactly the same error, so it's not my current "production" install having gone stale or unstable somehow.

Since the last time I assembled a panorama was, if I'm not mistaken, around Q1 2016 I suppose I was still running 9- or 10-RELEASE back then, and this is a regression.

Time to write up a bug report, I guess.


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