Greg's enblend problems

This page describes a bug in enblend that has since been resolved. I'm leaving it here for hysterical raisins.

This page describes a problem I ran into on 14 February 2013 while upgrading the FreeBSD enblend port from version 4.0 to version 4.1. The compilation went well, and after installation I tried running Hugin against an existing project file. The results were surprising. I wrote the following and then continued investigating. I'm not done yet, but it seems that enblend 4.1 can no long stitch 360° panoramas.

Here's the panorama as it should be, followed by what enblend 4.1 generated:

https://lemis.nyc3.digitaloceanspaces.com/grog/Photos/20130209/big/garden-centre-enblend-4.0.jpeg

Image title:	garden centre enblend 4.0	Dimensions:	9139 x 2754, 8192 kB
Make a single page with this image		Hide this image
Make this image a thumbnail		Make thumbnails of all images on this page
Make this image small again		Display small version of all images on this page
All images taken on Saturday, 9 February 2013, thumbnails		All images taken on Saturday, 9 February 2013, small
Diary entry for Saturday, 9 February 2013		Complete exposure details

https://lemis.nyc3.digitaloceanspaces.com/grog/Photos/20130209/big/garden-centre-enblend-4.1.jpeg

Image title:	garden centre enblend 4.1	Dimensions:	9139 x 2754, 4688 kB
Make a single page with this image		Hide this image
Make this image a thumbnail		Make thumbnails of all images on this page
Make this image small again		Display small version of all images on this page
All images taken on Saturday, 9 February 2013, thumbnails		All images taken on Saturday, 9 February 2013, small
Diary entry for Saturday, 9 February 2013		Complete exposure details

One image is missing completely, and another one is missing partially. Apart from that, everything looks the same. Run the cursor over the images to see the differences. Running enblend from the command line shows no anomaly, but generates the same image.

=== grog@eureka (/dev/pts/14) ~/Photos/Hugin-build-eureka 83 -> enblend --compression=LZW -m 6000 -w -f9139x2754+0+1159 -o garden-centre-enblend-4.1.1.tif -- garden-centre00*tif enblend: info: loading next image: garden-centre0000.tif 1/1 enblend: info: loading next image: garden-centre0001.tif 1/1 enblend: info: loading next image: garden-centre0002.tif 1/1 enblend: info: loading next image: garden-centre0003.tif 1/1 enblend: info: loading next image: garden-centre0004.tif 1/1 enblend: info: loading next image: garden-centre0006.tif 1/1 enblend: info: loading next image: garden-centre0007.tif 1/1 enblend: info: loading next image: garden-centre0008.tif 1/1 enblend: info: loading next image: garden-centre0009.tif 1/1 enblend: info: loading next image: garden-centre0011.tif 1/1 enblend: info: loading next image: garden-centre0012.tif 1/1 enblend: info: loading next image: garden-centre0013.tif 1/1 enblend: info: writing final output

The image garden-centre0011.tif, which doesn't look unusual in any way, is missing completely. In addition, what appears to be the top left part of garden-centre0013.tif is also missing to the right. The missing image numbers in the file name list are really not part of the panorama.

This zip archive contains 1/16th size versions of the images. The problem can be reproduced with the following commands, modified to adjust the size:

enblend-4.0 --compression=LZW -w -f2285x689+0+290 -o garden-centre-4.0.jpeg -- garden-centre00* enblend-4.1 --compression=LZW -w -f2285x689+0+290 -o garden-centre-4.1.jpeg -- garden-centre00*

This assumes that you have enblend executables with those names, of course.

There's a bogus problem here that I don't understand: enblend 4.0 creates a highly pixellated image. That doesn't happen with the original sized images.

I have entered a bug report, #1124837, against this problem.