This demo illustrates how to identify similar documents, or filled documents of an empty form. Firstly, choose your form from an image as a template, and add as many images as you want to that template if there are slight varieties. Secondly, create more than one template. And finally, choose the image you want to identify the template for and just press "Identify Document...".
Available in both C# and VB.NET in the WinForm folder, also available as a compiled application in the Bin folder located in [INSTALLATION FOLDER]/Samples/.