Method for extracting region of interest of finger vein image based on correction of rotation

Abstract

The invention aims at providing a method for extracting the region of interest of a finger vein image based on the correction of rotation. Firstly, dividing a finger region of a read-in finger vein image by employing a Kapur entropy threshold method; then, calculating a center of mass of the image and the center of mass is used as a reference for the correction of rotation, and determining a position of the region of interest based on the project values of pixels on each column of the image in a vertical direction and internal tangent lines of the upper and the lower edges of a finger outline; finally, normalizing samples of the image for obtaining a final processing result. Due to the problems that non-linear factors such as rotation, translation, etc. in the sampling of the finger vein image exert a significant impact on the image quality, and that the finger vein image positioning is difficult, the method brings up with a new solution which fully considers the characteristics of the non-contact sampling of the finger vein image and extracts the region of interest of the image based on the correction of rotation, and thus effectively improves influences of the image quality and enables the identification to be more reliable.

Description

technical field [0001] The invention relates to a vein feature extraction method in the technical field of pattern recognition. Background technique [0002] Vein recognition is a highly reliable identification method, and its recognition performance is closely related to the quality of vein target extraction, because biometric recognition technology must compare the features of the same pattern in the same area to achieve the desired effect. The area is the ROI (Region of Interest). [0003] At present, there are few related studies on the determination of the region of interest in the finger vein image acquired by non-contact acquisition methods, but most of the methods for extracting the region of interest in the palmprint and palm and back vein images rely on the introduction of positioning auxiliary devices. Although the literature " Research on Hand Feature Recognition and Feature-Level Fusion Algorithm (Li Qiang. Ph. The index structure information of . However, fi...

AI Technical Summary

Problems solved by technology

[0003] At present, there are few related studies on the determination of the region of interest in the finger vein image acquired by non-contact acquisition methods, but most of the methods for extracting the region of interest in the palmprint and palm and back vein images rely on the introduction of positioning auxiliary devices. Although the literature " Research on Hand Feature Recognition and Feature-Level Fusion Algorithm (Li Qiang. Ph. The index structure information of

However, the fingers are slender and straight, and do not have this characteristic, so that the above method cannot be used for the determination of the region of interest of the finger vein.

Images