Installing the Plug-in

Installation using pre-built binaries
Building from Sources

The Image Registration plug-in comes in two different flavors:

as a Python script, and
as a native plug-in completely implemented in C/C++

Both versions are functionally identical. They even share the same numerical part, which is written in C++ and does the heavy lifting of iteratively determining the alignment parameters. The only reason for devising the Python version of the plug-in was the fact that the Gimp development libraries, which are needed for the native implementation of the plug-in, are not readily available for all operating systems.

Please note that for using the Python version of the plug-in, it is necessary that your Gimp installation has Python scripting support. You can easily check this by examining the Filters menu, which will contain an entry named Python-Fu if your Gimp has Python scripting support.

Installation using pre-built binaries

For installing the plug-in, download the pre-built binaries for your system from

https://sourceforge.net/projects/gimp-image-reg/files/version-2.0.1/

and unpack it to some folder on your computer.

Then, start Gimp and add that folder to the list of Gimp's plug-in folders, which you find at

Edit → Preferences → Folders → Plug-Ins

After restarting Gimp, the plug-in will be available as Image Registration... under the menu Tools.

Building from Sources

For building the Python version of the plug-in from the sources you will need

cmake, version 3.13 or newer, and
a C/C++ compiler together with build tools such as make, ninja, etc.

Further, for building the native version, you will additionally need

pkg-config and
the Gimp development libraries libgimp-2.0.

Building the plug-in from sources will typically involve the following steps:

Download the source archive gimp-image-reg-2.0.1-source.zip and unpack it to some folder. For example:
```
$ unzip gimp-image-reg-2.0.1-source.zip -d imreg-sources
          
```
Create a folder in which you will build the binary. It is a matter of your personal preference to have this folder inside or outside the source folder. In this example, let's have this folder outside the source folder:
```
$ mkdir imreg-build
          
```
Step into the build folder and init the cmake build environment specifying the source and build folders:
```
$ cd imreg-build
$ cmake -S ../imreg-sources -B .
          
```

While in the build folder, build and install the plug-in:

$ cmake --build .
$ cmake --build . --target install

The previous step will install the plug-in into a folder named install in the build directory. Now you can add this directory to the list of Gimp's plug-in folders, and upon restarting Gimp, the plug-in will appear as Image Registration... in Gimp's Tools menu.

For further examples, refer to the various shell and batch scripts which are included in the scripts directory inside the source folder. In that folder you will also find a Python script named create_build_system.py, which can be helpful for creating build environments, specially when working with Visual Studio.