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    <p>I used Tesseract via Tessnet2 recently (Tessnet2 is a VS2008 C++ wrapper around Tesseract 2.0 made by Rémy Thomas, if I remember well). Let me try to help you with the little knowledge I have concerning this tool:</p> <ul> <li><p>1st, as I said above, this wrapper is only for Tesseract 2.0, and the <a href="http://code.google.com/p/tesseract-ocr/" rel="noreferrer">newest Tesseract version on Google Code</a> is 3.00 (the code is no longer hosted on Source Forge). There are regular contributors: I saw that version 3.01 or so is planned. So you don't benefit from the last enhancements, including page layout analysis which may help when your license plates are not 100% horizontal.</p></li> <li><p>I asked Rémy for a Tessnet2 .NET wrapper around version 3, he doesn't plan any for now. So as I did, you'll have to do it by yourself !</p></li> <li><p>So if you want to get the latest version of the sources, you can download them from the <a href="http://tortoisesvn.tigris.org/" rel="noreferrer">Subversion</a> repository (everything's described on the <a href="http://code.google.com/p/tesseract-ocr/source/checkout" rel="noreferrer">dedicated site page</a>) and you'll be able to compile them if you have Visual Studio 2008, since they sources contain a VS2008 solution in the <code>vs2008</code> sub-folder. This solution is made of VS2008 C++ projects, so to be able to get results in C# you'll have to use .NET P/Invoke with the <code>tessDll</code> built by the project. Again if you need this, I have code examples that may interest you, but you may want to stay with C++ and do your own new WinForm projects, for instance !</p></li> <li><p>When you have achieved to compile (there should not be major problems for that, but tell me if you meet some, I may have met them too :-) ), you'll have in output several binaries that will allow you to do a specific training ! Again, there is <a href="http://code.google.com/p/tesseract-ocr/wiki/TrainingTesseract3" rel="noreferrer">a page specially dedicated to Tesseract 3 training</a>. Thanks to this training, you can:</p> <ul> <li><p>restrain your set of characters, which will automatically remove the punctuation ('/-\' instead of 'A', for instance)</p></li> <li><p>indicate the ambiguities you have detected ('D' instead of 'O' as you could see, 'B' instead of '8' etc) that will be taken into account when you will use your training.</p></li> </ul></li> <li><p>I also saw that Tesseract results are better if you restrain the image to the zone where the letters are located (i.e. no face, no landscape around): in my case, I needed to recognize only a specific zone of cards photos taken from a webcam, so I used image processing to restrain the zone. That was long, of course, but my images came from many different sources so I had no choice. If you can get images that are restrained to the minimum, that will be great !</p></li> </ul> <p>I hope it was of any help, do not hesitate to give me your remarks and questions !</p>
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    1. COThanks so much for the comprehensive reply! Was thinking maybe Tesseract 3 could possibly help in terms of recognition if changes related to font styles have been replaced, although I doubt this is the case. As you mentioned, the code is available in VS2008, therefore a wrapper shouldn't be required, however I have no idea how to do a .NET P/Invoke, especially with this library, therefore any advice you could provide with this, including compiling the functionality in a DLL similar to Tessnet2 would be great!
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    2. COP/Invoke is a way to communicate between managed (C#, VB) and unmanaged (unmanaged C++ for instance, such as this VS2008 project) DLLs. I had to use it because I had to interface with C#, but if you can stay with C++ only, no need for P/Invoke. Now if you really need it, I'll show you an example !
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