ResX Generator (RESXGEN)
The ResX Generator (ResXGen) is a console utility that converts an image file (such as a .jpg or .bmp file) into an XML-formatted .resx file, which can then be compiled into a .NET-compatible .resources files using Resgen.exe.
The following lines of code from ResXGen (abridged for readability) show the essential process for creating a .resx file from an image file.
Image img = Image.FromFile(ap.InputFile);
ResXResourceWriter rsxw = new ResXResourceWriter(ap.OutputFile);
rsxw.AddResource(ap.ResourceName, img);
rsxw.Close();
The necessary XML schema is documented in the .NET Framework — specifically, in the ResourceSchema property of the ResXResourceWriter class. This functionality is also encapsulated by ResXGen, so to view the schema, it is necessary only to run the following command:
ResXGen /schema