Editing Fingerprint (section)

== Algorithms ==
Matching [[algorithms]] are used to compare previously stored templates of fingerprints against candidate fingerprints for [[authentication]] purposes. In order to do this either the original image must be directly compared with the candidate image or certain features must be compared.<ref name=UCSDBiometric>{{cite web |url=http://cseweb.ucsd.edu/classes/fa08/cse237a/finalproject/smazumdar_final_report.pdf |title=Biometric Security Using Finger Print Recognition |first1=Subhra |last1=Mazumdar |first2=Venkata |last2=Dhulipala |year=2008 |publisher=University of California, San Diego |page=3 |accessdate=30 August 2010 |archive-date=October 8, 2011 |archive-url=https://web.archive.org/web/20111008112350/http://cseweb.ucsd.edu/classes/fa08/cse237a/finalproject/smazumdar_final_report.pdf |url-status=live }}</ref>

=== Pre-processing ===
Pre-processing enhances the quality of an image by filtering and removing extraneous noise. The minutiae-based algorithm is only effective with 8-bit gray scale fingerprint images. One reason for this is that an 8-bit gray fingerprint image is a fundamental base when converting the image to a 1-bit image with value 1 for ridges and value 0 for furrows. This process allows for enhanced edge detection so the fingerprint is revealed in high contrast, with the ridges highlighted in black and the furrows in white. To further optimize the input image's quality, two more steps are required: minutiae extraction and false minutiae removal. The minutiae extraction is carried out by applying a ridge-thinning algorithm that removes redundant pixels of ridges. As a result, the thinned ridges of the fingerprint image are marked with a unique ID to facilitate the conduction of further operations. After the minutiae extraction, the false minutiae removal is carried out. The lack of the amount of ink and the cross link among the ridges could cause false minutiae that led to inaccuracy in fingerprint recognition process.{{citation needed|date=June 2019}}

=== Pattern-based (or image-based) algorithms ===
Pattern based algorithms compare the basic fingerprint patterns (arch, whorl, and loop) between a previously stored template and a candidate fingerprint. This requires that the images can be aligned in the same orientation. To do this, the algorithm finds a central point in the fingerprint image and centers on that. In a pattern-based algorithm, the template contains the type, size, and orientation of patterns within the aligned fingerprint image. The candidate fingerprint image is graphically compared with the template to determine the degree to which they match.<ref name=ibia><!-- Minutia vs. Pattern Based Fingerprint Templates. (2003). Retrieved 13 December 2005, from http://web.archive.org/web/20070929083052/http://www.ibia.org/membersadmin/whitepapers/pdf/9/M_vs_P_White+Paper_v2.pdf (archived from www.ibia.org on 2007-09-29) -->[http://files.spogel.com/projects/t-000145--Fingerprint_Methods.pdf Minutia vs. Pattern Based Fingerprint Templates] {{Webarchive|url=https://web.archive.org/web/20170107120130/http://files.spogel.com/projects/t-000145--Fingerprint_Methods.pdf |date=January 7, 2017 }} Identix Incorporated Issued 26 March 2003</ref>