FINGERPRINT POST PROCESSINGminutia extraction and false minutia removal

M.IMRAN BAIG EE083050KHAWAR HAYAT EE083069ABID ALI EE083103

Given images

• Binary image• Orientation• Mask• Thinned image

Algorithm

• Rotation mask method

• Crossing number algorithm

Rotation mask method0 1 0

0 1 0

0 0 0

1 0 1

0 1 0

0 1 0

Rotate mask 45 degree and compare with the image

Minutia Detection

8

1191 |,|5.0

iii PPPPCN

Minutia Detection Cont’d

0 1 0

0 1 0

0 0 0

1 0 1

0 1 0

0 1 0

Bifurcation =ABS((0-0)+(0-1)+(1-0)+(0-0)+(0-1)+(1-0)+(0-1)+(1-0))=6

Minutia termination=ABS((0-0)+(0-0)+(0-0)+(0-0)+(0-0)+ (0-1)+(1-0)+(0-0))=2

Minutia Detection Cont’d

False Minutia Removal

• Create an image of minutia• Take a chunk around a minutia point • Compare that image with given mask image• If these are at the edge then remove that

minutia

False Minutia Removal Cont’d0 1 1

1 0 1

1 1 1

1 0 0

1 0 0

1 0 0

0 0 0

1 0 0

1 0 0

0 1 1

1 0 1

1 1 1

1 1 1

1 1 1

1 1 1

0 1 1

1 0 1

1 1 1

Minutia in image sum=7 * Mask output sum=2

Minutia in image sum=7 * Mask output sum=7

False Minutia Removal Cont’d

False Minutia Removal Cont’d

• Now remove these pattern

False Minutia Removal Cont’d

• Take an array, size is nearly equal to distance between two lines. We take25x25 because distance between lines is around 14 pixel.

• Find the minutia and take a chunk of 25x25.• If there is minutia within this window then

remove both minutia.• If there is bifurcation then remove the

termination and bifurcation because it is a spike.

False Minutia Removal Cont’d1

1

1

1

1

1

1

1 1

1 1

1 1

1

1 1

1

False Minutia Removal Cont’d

• Like we take window around the termination we also take the window around the bifurcation

• Find if there is more than one bifurcation within the window remove both bifurcation because it is hole.

False Minutia Removal Cont’d

1

1

1

1 1 1

1

1

1

1

1

1 1 1

1 1

1 1

1 1 1

1

False Minutia Removal Cont’d1

1

1

1

1

2

1

1

1

3

False Minutia Removal Cont’d1 1

1 1

1

1

1

1 1

1

1 1

1 1

1 1

1

1

1

1 1

1 1

1 1

False Minutia Removal Cont’d

References

• Rohit Singh , Utkarsh Shah , Vinay Gupta Indian Institute of technology, Kanpur

• Fingerprint Image Enhancement and Minutiae Extraction, Raymond Thai, The University of Western Australia

THANK YOU