Photo Stitchers

http://www.hants.lug.org.uk/images/flav.sized.jpg

One of the advantages of using a digital camera is the ability to manipulate images on a computer without messing around with scanners and negatives. Many digital cameras have modes to help take many individual photos that can be digitally joined later to create a larger composite. (You don't need a camera with such a mode to take photos for stitching – any sequence of photographs with at least 33% overlapping material will do!) Some digital cameras come supplied with software (usually for Windows) that can stitch images together but the Linux solutions are still relatively new.

This document covers installing software to stitch together multiple images on Debian Etch. There are RPM packages available for two of the three programs mentioned from the project website. There are also Windows binaries available in some cases.

Installation using apt

Christian Marillat's repository now provides packages for hugin and enblend, and the panorama tools are in the main Etch package repositories. To add Marillat's repository, add the following line to your /etc/apt/sources.list file:

deb ftp://ftp.nerim.net/debian-marillat etch main

• Then run

apt-get clean && apt-get update

• before proceeding. Install the packages covered here and their dependencies using:

apt-get install libpano12-bin hugin enblend autopano-sift

• N.B. if you have previously installed the panorama-tools package on the advice of this page, you must remove it before trying the above step.

Usage

Panorama Tools

The panorama tools collection can be used from the command line to stitch multiple images together, but it really designed to be invoked via Hugin. Working with graphics is much easier from a GUI If you want to find out more about Panorama Tools, check the website for documentation and sample output.

Hugin

Hugin is a GUI for Panorama Tools written in C++. The program is beta software and has a few bugs, so save your work often as you go along.

Start Hugin from the command line by entering hugin. If you installed via apt then a menu item should be created for you automatically. If you want to add Hugin to your menu system manually, create a file called hugin in /etc/menu and give it the following contents:

?package(local.hugin): needs="X11" section="Apps/Graphics" title="Hugin" command="hugin"

Save the file and run the update-menus command. You may need to restart your window manager before Hugin will appear in the Graphics menu.

You can check out the Hugin tutorials for more information. With Hugin 0.5 you must use the Nona stitching option.

Enblend

Enblend is an extra tool to complement Hugin. It is designed to balance out colour differences between joins in stitched images. The Enblend website gives the prerequisites as:

• A fast computer.
• Lots of memory.
• Lots of disk space for temporary files.

From version 0.5, Hugin can invoke enblend automatically without the need for a separate step. Simple choose TIFF output with the "soft blending" option ticked.

If you want to use Enblend manually, prepare your stitched image in Hugin, but choose the "Multiple TIFs" option when stitching. This saves each constituent image in the panorama in a separate file rather than blending them together. Then, run enblend in the directory, specifying output and input files:

enblend -v -o output.tif input.tif ...

Check out the Enblend website for more information.

Autopano-SIFT

Hugin 0.5 also has an option to invoke Autopano-SIFT, which finds matching control points for you, and makes a surprisingly good job of it.

Purists may like to investigate Autopano-SIFT's US patent-pending issues, and the licensing demands of The University of British Columbia. Read more here.

Autopano-SIFT can be used on its own, but Hugin can be configured to invoke it by entering the location of the autopanog binary (or autopanog.exe executable if you compiled from source) and clicking on the relevant button.

AutoStitch

This is an incredible panorama tool, and does a wonderful job of automatically piecing together many photographs into one seamless panorama, automatically adjusting contrast, colours etc. There is a demo version available on the website AutoStitch which apparently runs under wine. I haven't got round to trying it, but the results from seeing its use by friends on their windows machines are fantastic.

 

The image at the head of the page is by TonyWhitmore, from his Gallery. The panorama below is an early attempt by ChrisDennis.

http://www.fb-cs.co.uk/images/treeline.jpg