object recognition in csharp

First to look at is AForge.NET, see http://en.wikipedia.org/wiki/AForge.NET[^], http://www.aforgenet.com/[^].

Also look at the following libraries:

OpenCV, http://en.wikipedia.org/wiki/OpenCV[^], http://opencv.willowgarage.com/wiki/[^],

VXL, http://en.wikipedia.org/wiki/VXL[^], http://vxl.sourceforge.net/[^].

See also the articles by the author of AForge.NET, CodeProject member Andrew Kirillov: http://www.codeproject.com/Members/Andrew-Kirillov[^]. Another CodeProject member to look at is Chesnokov Yuriy, http://www.codeproject.com/Members/Chesnokov-Yuriy[^].

If you contact them, don't tell them you've done it on my advice. :-)

—SA

The best approach is to usually perform some preprocessing so that your sample image is noise free and your object is easily distinguishable. This preprocessing stage may also include aligning your image to a consistent orientation to that of any sample you may wish to use for comparison.

Once you have an image which is in a form it can easily be analysed, you may wish to compare your object to stock example using a metric such as Mean Squared Error. The less the disparity between your sample and example image, the higher the likelihood of a match.

However, this would work in the case of simple object such as geometric shapes. However if you wanted to recognise an image of a cup this would be difficult. Would you provide an exhaustive list of every type of cup design? Another layer of complexity would be to ask, is your recognition semantic? Do you want to be able to realise from any cup shape, that it's function is in fact to hold liquid. How would you differentiate from a bowl in that case?

These are not trivial questions and are the focus of serious research.

I upvoted SA's solution here because of the relevant links. I would also recommend starting with AForge and seeing how far you get.