Fuzzy Logic/ Fingerprint Question

Hi,

I'm working on fuzzy fusion in multimodal biometric systems! so I'm trying to Implement an authentication system using two finger prints, and so I'd study a paper with this title : "Fuzzy Fusion in Multimodal Biometric Systems" written by : "Vincenzo Conti, Giovanni Milici, Patrizia Ribino, Filippo Sorbello, and Salvatore Vitabile".

In this paper, the decision level fusion and the matching level fusion were evaluated using two fingerprints based subsystems. The whole recognition system also incorporates the knowledge about the image quality. Image quality is based on both ES(Erased Segments) and CM(Candidate Minutiae) features. Experimental trials aimed to find a global image Goodness Index (GI) in term of ES and CM values were performed.

This Figure shows the ES and CM ranges with relative membership function values and the membership function range of the GI :

These are ES, CM and GI ranges.

This paragraph in the paper tell us more information about GI :

The Goodness Index GI=f(ES, CM) is obtained applying “moment defuzzify function” [16]. The moment defuzzify function returns a defuzzified floating point value, which represents the defuzzified fuzzy set using the centre of gravity (or first moment of inertia) function. The centroid method is a good method to use in many processes since it tends to smooth out the fuzzy region [16]. Figure 3 shows three different fingerprint images with a different GI value. The image on the left is a fingerprint of good quality, GI=82.01, on the center a fingerprint of medium quality, GI=55.01, and on the right a fingerprint of bad quality, GI=0.

I want to calculate GI but I don't know how can I implement these fuzzy systems?

I have not any more information about it. Can I calculate fuzzy rules just by this figure?

Please help me...

[Younes Jafari]

somebody help me...