Can't find System.Windows.Media namespace?

You should add reference to PresentationCore.dll.

The System.Windows.Media.Imaging namespace is part of PresentationCore.dll (if you are using Visual Studio 2008 then the WPF application template will automatically add this reference). Note that this namespace is not a direct wrapping of the WIC library, although a large proportion of the more common uses are still available and it is relatively obvious how these map to the WIC versions. For more information on the classes in this namespace check out

http://msdn2.microsoft.com/en-us/library/system.windows.media.imaging.aspx

Add PresentationCore.dll to your references. This dll url in my pc - C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\.NETFramework\v4.5\PresentationCore.dll