A very popular open source C# project for image processing, neural networks, machine learning etc. is the
AForge.NET Framework, developed by Andrew Kirillow.
AForge.NET has been used in
numerous applications. It also forms the basis for the
Accord.NET Framework, developed by César de Souza, which substantially extends
AForge.NET with additional image processing filters, machine learning algorithms, statistical distributions and much much more. Numerous examples of what Accord.NET Framework is capable of are available
here.
AForge.NET was developed to run on the
.NET Framework and uses the
System.Drawing assembly as basis for image manipulation and processing. In particular the dependency on
System.Drawing heavily limits the applicability of
AForge.NET (and subsequently,
Accord.NET) to more modern platforms, like
WPF,
Windows (for tablet and desktop, as opposed to desktop-only applications), and
Windows Phone.
It seemed like a terrible waste that these frameworks would only be available to the outdated range of
Windows Forms applications. So, to enable the invaluable functionality of
AForge.NET and
Accord.NET for modern Microsoft platforms, I started the project of porting these frameworks into
Portable Class Libraries, PCL. These efforts are also open sourced and are available on Github:
Portable AForge and
Portable Accord.
It should be noted that
Portable AForge and
Portable Accord cover a subset of the assemblies in the pure .NET based frameworks. Video and robotics support is not included, and audio support is limited.
Windows Forms UI controls have not been ported. Nevertheless, practically all image processing and scientific computing functionality is included in the portable frameworks.
To facilitate continuous inclusion of updated code for the two frameworks, I have striven to keep the original
AForge.NET and
Accord.NET code bases as untouched as realistically possible. To cover up for those parts of the framework codes that are not applicable in the portable class libraries, I have therefore developed two support assemblies called
Shim and
Shim.Drawing.
Shim, which contains simple implementations of non-UI types and methods unavailable in the PCL profiles, is maintained in a
separate Github repository, since this assembly is also immediately applicable as a legacy code bridge in other modern target adaptations, such as the port of the
fo-dicom library to the (modern)
Windows and
Windows Phone platforms.
Shim.Drawing is internal to the
Portable AForge and
Accord assemblies, and is contained in the
Portable AForge Github repository. It provides a down-scaled replacement for the
System.Drawing assembly. Along with the platforms of primary interest,
Shim.Drawing can also be contained in a .NET Framework
WPF project as long as
System.Drawing is not simultaneously referenced.
Portable AForge and
Accord is thus a also shortcut to using
AForge.NET and
Accord.NET in
WPF applications.
To enable the portable framework assemblies on a specific target platform, the
Shim and
Shim.Drawing assemblies come in various flavors. There are for example specific
Windows Phone (Silverlight) 8 versions of
Shim and
Shim.Drawing that should be referenced in a
WP8 application using the
Portable AForge and
Accord assemblies.
Currently,
Portable AForge and
Portable Accord are available for the following target platforms:
- .NET Framework 4.5 and higher (for WPF applications)
- Windows 8 and higher (modern tablet/desktop applications)
- Windows Phone Silverlight 8 and higher
- Universal applications, i.e. Windows Phone 8.1 + Windows 8.1
- Xamarin.iOS
- Xamarin.Android
Yes, you read it right! My most recent developments also incorporate the ability to target the
Xamarin.iOS and
Xamarin.Android platforms. The
Xamarin assemblies are however not available as open source. If you are interested in developing
AForge and
Accord based applications for
Xamarin.iOS and/or
Xamarin.Android, please contact me directly at
licenses@cureos.com.
And now, with
AForge and
Accord available on the three mobile platforms, cross-platform development using
Xamarin.Forms has also become a reality! This means that it is practically possible to contain an entire C# code base in a PCL core library that uses
AForge and
Accord, and consume this core library from end applications for all three mobile platforms,
Windows Phone,
Xamarin.iOS and
Xamarin.Android.
Just to show what can now be very quickly done, I copied the functionality of the
Face Detection (Haar Object Selector) sample application from the
Accord.NET samples and contained it in a
Xamarin.Forms project. All application code, including setting up the graphical layout and the face detection operation, is contained in the PCL core project. The platform specific end application projects only wrap the core assembly.
And this is what the face detection sample application looks like on the three mobile platforms:
A first small step, perhaps, but the possibilities that have now been opened up are practically infinite :-)
