Enhancement method of fingerprint image

Abstract

The invention discloses an enhancement method of a fingerprint image, which comprises the following steps: analyzing at the angle of a frequency domain and removing the high-frequency component of an image by the fuzzy processing of an original image; then, subtracting the fuzzed fingerprint image by utilizing the original image to remove the low-frequency component of the image so as to obtain comparatively pure image high-frequency information, wherein the low-frequency information of the image is already removed basically; and afterwards, superposing with the original image to obtain the image the high-frequency part of which is enhanced, i.e. the sharpened image. Further, the influence of the nonuniformity of an illumination field is eliminated by utilizing the difference of the sharpened image and the sharpened image processed by fuzzification. Thus, the obtained enhanced fingerprint image is relatively ideal and is convenient to select a threshold value in a subsequent image processing process when binaryzation processing is carried out on the fingerprint image, thereby lowering the probability of the erroneous extraction of the characteristic of a fingerprint and enhancing the accuracy of fingerprint identification.

Description

technical field [0001] The invention relates to a fingerprint image preprocessing method, in particular to a fingerprint image enhancement method. Background technique [0002] With the progress of society, people pay more and more attention to the security of identification. Traditional identification often uses certificates, passwords and other methods. However, credentials can be lost or copied; passwords can be easily forgotten or confused. Especially with the advent of the Internet era, more and more password settings are bothering people: power-on passwords, email passwords, bank passwords, forum passwords... For these, if the same password is set, it will increase security risks ; If different passwords are set, it will cause trouble for password management. For this reason, identification technology based on biometrics (such as fingerprints, faces, irises, etc.) is gaining more and more attention. Among them, fingerprint recognition has a high recognition rate an...

AI Technical Summary

Problems solved by technology

However, these methods either enhance the background noise while enhancing the fingerprint lines, or blur the fingerprint lines while reducing the background noise.

For this reason, when the collected fingerprint images are not clear enough and the ridge lines are difficult to identify, the processing effect of the existing fingerprint image enhancement technology is very poor, which often leads to wrong extraction of fingerprint features.

In addition, when the fingerprint itself is seriously scratched or worn, the processing effect of the existing fingerprint image enhancement technology is also difficult to meet the requirements.

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