反射眩光於虹膜取像系統之研究

Abstract

在虹膜辨識系統中，反射眩光是一個很大的議題，在擷取虹膜影像時，近紅外線光源所產生的反射眩光會遮蔽在虹膜區域，因此影響到整體的辨識率。本篇論文提出完整數學模型，藉由調整光源設置去改變反射眩光出現的位置，也就是調整待測者、光源及影像擷取裝置三者間的幾何關係，就可以控制反射眩光出現的位置，以達到反射眩光不會遮蔽虹膜的資訊。最後，本篇論文以完整實驗結果驗證數學模型的準確性，並修正模型誤差。

Specular reflection is an important issue for an iris acquisition imaging system. This thesis is aimed to investigate the influence of near IR source on the image quality as well as optimizing arrangement of light source to enhance segmentation process. The arrangement of the light source manipulates the specular positions on iris region. More specifically, by controlling the geometric relations of subject, light source and image acquisition is able to avoid the specular reflections overlapping with iris information region. In this thesis, we proposed a complete geometric model to predict the specular reflections. The effectiveness and practicability of the proposed modeling have been validated by a series of experimental testing.