How to search for famous logo in scanned image?

Question

I have following scanned document, with the logo on it, and I have another black and white image with same logo and style (Shown in black and white color below).

How do I make sure that the logo is present on this image or not?

Usually I will have many scanned documents, OCR will pickup MTNL, but sometimes these logos are just made up of symbols not recognized easily by OCR.

Size and position of logos change, they are not fixed many times. They may be placed anywhere on the document.

I want to organize and catalog scanned images based on the logos and symbols present. Most documents may or may not be in english, may or may not contain any bar codes, in such case logo match will help.

I have seen Aforge.NET library, but I am not very much sure which methods to combine to do search. Pixels search is very slow and fails if source destination are of different size.

I have heard that YouTube does some sort of Histogram or Heat Signature match to see if the video contains any copyrighted material. I will be helpful if someone can guide me in this case.

My ideal choice would be C# and Aforge.NET, otherwise some command line tool will be appreciated.

Answer 1

You can try using Aforge.net
Check these links
1) http://www.aforgenet.com/articles/shape_checker/
2) http://www.codeproject.com/Articles/9727/Image-Processing-Lab-in-C
3) http://www.aforgenet.com/forum/viewtopic.php?f=4&t=323

Answer 2

Detect useful features in your logo image, and look for those features in the scanned document. SIFT is a useful feature descriptor that is scale and rotation invariant. Other descriptors include SURF and HOG.

If you look around, there will be plenty of implementations, some of them even in C#.