Missing image parts with graphcut seam generator

[Anton]

In certain situations, enblend seems to just completely skip an image. So far it has only happend with an image on the bottom edge of the panorama, but who knows...
Messing around with the crop, resolution and what images to include changes the behavior, so it seems kind of random. Happens both with multithreading and a single thread.

This only happens in enblend 4.2, going back to 4.1.5 fixes the problem. Not sure whether the fault is in Hugin (bad or out of date command line) or in enblend.

Here is a zip file with files needed to reproduce the bug (I hope):
http://ajpanton.se/hugin_enblend_bugreport.zip
I've removed as many input files as possible to make it smaller and faster to process. That's why there's so much empty space in the output.

Steps to reproduce:

1a. Have Windows (tested on Windows 10, 64-bit).
1b. Have enblend 4.2 (tested both with the "official" build and the one included in 2016.2 beta, both x64).
1c. Have Hugin (testeed with 2015.0 and 2016.2 beta, both x64) with default settings.
2. Open the .pto file with Hugin.
3. Stitch.

The output will look like "output 4.2.JPG", with one input image missing. enblend 4.1.5 does it correctly in "output 4.1.5.JPG"

[tmodes (tmodes)]

Moving it enblend bug tracker, because it not directly related to Hugin.
I was able to reproduce the issue. It happens only with graph-cut seam algorithm.
With nearest feature transform it works fine (add --primary-seam-generator=nft). So it needs fixed in the graph cut algorithm.

[bobemoe (bobemoe)]

I'm seeing what sounds like this same issue, but it is hard to tell because the original zip file is no longer available.

I'm stitching 360 spherical panoramics taken from a DJI drone. All images are present, overlapping and appear fine in the preview, but after final stitch, there are black/grey areas where an image has been missed. Usually one, sometimes two. They seem to be near the edge of the image.

I can confirm that --primary-seam-generator=nft fixes the issue.

I'm using:

enblend 4.2

Operating System: Linux 5.10.0-8-amd64 x86_64
Architecture: 64 bit
Hugin Version: 2020.0.0.2f576e5d5b4a

Libraries
wxWidgets: wxWidgets 3.0.5
wxWidgets Library (wxGTK port)
Version 3.0.5 (Unicode: wchar_t, debug level: 1),
Runtime version of toolkit used is 3.24.
Compile-time GTK+ version is 3.24.20.

libpano13: 2.9.20
Boost: 1.74.0
Exiv2: 0.27.3
SQLite3: 3.34.1
Vigra: 1.11.1
LittleCMS2: 2.9 Hugin 2020.0.0.2f576e5d5b4a