1 引言
指紋是指手指末端正面皮膚上凸凹不平產生的紋路。盡管指紋只是人體皮膚的一小部分，但是，它蘊涵大量的信息。這些皮膚的紋路在圖案、斷點和交叉點上是各不相同的，在信息處理中將它們稱作“特征”，依靠特征的唯一性，就可以把用戶同他的指紋對應起來，通過比較輸入的指紋特征和預先保存的合法指紋特征，就可以驗證用戶的真實身份。
以前的各種指紋識別系統屬于光學識別系統，由于光不能穿透皮膚表層，所以只能夠掃描手指皮膚的表面，或者掃描到死性皮膚層，但不能深入真皮層。在這種情況下，手指表面的干凈程度，直接影響到識別的效果。如果，用戶手指上粘了較多的灰塵，可能就會出現識別出錯的情況。并且，如果人們按照手指，做一個指紋手模，也可能通過識別系統，對于用戶而言，使用起來不是很安全和穩定。
本系統采用了凌陽SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A" title="SPCE061A">SPCE061A單片機作為控制核心，SPCE061A不僅僅是具有單片機的控制功能，它還是一款運算能力很強的DSP芯片；對于指紋的采集，本系統采用了富士通公司的新型指紋傳感器MBF300，這種電容傳感器發出的電子信號可以穿過手指的表面和死性皮膚層，達到手指皮膚的真皮層，直接讀取指紋圖案，從而大大提高了該系統的安全性。
2 系統設計
SPCE061A的指紋識別系統總體設計方案如圖1所示。
圖1 指紋識別系統總體設計方案
本系統采用凌陽公司的SPCE061A單片機，它是將控制功能、數據處理功能以及數字信號處理（DSP）功能集于一身的一種新型單片機。它的CPU采用凌陽最新推出的16位微處理芯片，工作頻率可達到40MHz。它的指令系統提供了16位乘法運算指令和內積運算指令，可以對指紋模板進行高速的DSP處理。它的內部采用總線結構，減少了各個功能部件之間的連線，提高了可靠性和抗干擾能力。它的結構采用模塊化，易于系統的擴展。它的中斷處理能力較強，適用于各種實時控制領域。它的地址線達到22根，可以擴展4M空間的程序和數據存儲器，適合指紋識別系統對存儲器容量較大的要求。它的低功耗和低電壓工作模式也使它特別適合于電池供電的指紋識別系統。
MBF300是富士通開發出的一種微型指紋傳感器，系統利用MBF300將采樣指紋模板輸入到單片機中進行比較分析。它是利用手指在傳感器表面滑動進行指紋的采樣，所以被稱為掃描型傳感器。
鍵盤和LCD都是I/O設備。鍵盤可以讓用戶修改信息和輸入ID號，增強該系統的安全性；LCD采用CHIPS65545，用于顯示界面信息,為防電磁干擾和信號衰減，LCD連接線必須作一些特殊處理。
3 MBF300傳感器的基本原理及特點
電容式傳感器可以將物體、圖形、文字等具有二維的圖象轉換成電信號。MBF300屬于電容式傳感器。它由一個2維金屬電極陣列構成。一端為固定極板，而人的手指皮膚則作為活動極板。當手指置于感應器上時，一個微細的信號從驅動環耦合到手指真皮表層上，并隨著指紋的紋脊和紋谷的變化而變化。感應器偵測這種細微變化，對感應信號放大，經模數轉換后，從而最終形成精確的指紋圖象。
3．1 MBF300傳感器的基本原理
MBF300電容式傳感器的基本原理如圖2所示。
圖2 MBF300傳感器的基本原理圖
S是固定極板，H為活動極板，即用戶的手指指紋。當活動極板因被測參數的改變而引起移動時，兩極板間的距離d發生變化，從而改變了兩極板之間的電容量。設兩極板相互覆蓋的有效面積為A(M2)，兩極板間的距離為d（M），板極間介質的介電常數為ε(F·m-1)，在忽略板極邊緣影響的條件下，其靜態電容量C（F）為：
3．2
MBF300傳感器的特點
MBF300表面保護膜異常堅硬，使得該傳感器經久耐用。它的工作電壓為2.8V～5V，所以可以利用電池進行供電。它具有256*32像素感應矩陣，使得指紋的特征采樣數據更精確。它的總線接口分別支持USB1.1、增強型8位微處理器接口和SPI串行接口。SPCE061A利用USB接口芯片PDIUSBD12和MBF300指紋傳感器進行通信。
4軟件設計
4．1指紋識別算法
人類的指紋由緊密相鄰的凹凸紋路構成，根據公式3-2，通過對每個像素點上利用標準參考放電電流，便可檢測到指紋的紋路狀況，具體算法分為四部分。
4．1．1指紋識別預處理算法
指紋識別預處理的目的是使指紋圖像更清晰，邊緣更明顯，以便提取指紋的特征點進行識別。本文采取極值濾波和改進的平滑濾波進行噪聲消除，使圖像不失真；采取拉普拉斯銳化對指紋進行紋線增強，突出邊緣信息，為背景分離算法提供方便。
4．1．2背景分離
采用迭代閥值的方法對指紋圖像進行閥值分割。在圖像處理中，反復地用一種運算直至條件滿足而得到輸出圖像的方法稱為迭代。迭代閥值方法如下：
①設定初始灰度閾值T（如令T=127），指指紋圖像的灰度值分為兩組R1和R2。
②計算兩組的平均灰度值u1和u2。
③重新設定新的灰度閾值T。新的T定義為：T=（u1+u2）/2。
④依據新的T對指紋圖像進行閥值分割。
這種方法是以自適應的閥值對指紋圖像進行二值化處理。實驗結果表明，該方法比設定固定閥值進行處理更有普遍意義，且行之有效。
4.1．3 特征點提取
采用脊跟蹤法，其基本思想是直接對圖象進行脊線跟蹤，在跟蹤過程中檢測和提取特征點。
4.1．4分類算法
指紋被分成5大類：拱類、做環類、右環類、尖拱類和旋渦類，預先使用全局特征排序，可以加速指紋的匹配服務。
4．2程序流程
當系統處于空閑狀態時，SPCE061A利用P_SystemClock單元寫入CPUCLK STOP控制字，使系統從運行狀態轉入睡眠狀態，關閉系統時鐘（PLL振蕩器）。當用戶有指紋或按鍵輸入時， 系統接收到喚醒信號后接通PLL振蕩器，同時CPU會響應喚醒事件的處理并進行初始化。利用IRQ3_KEY為觸鍵喚醒源，利用FIQ為MBF300指紋傳感器輸入喚醒源。下面是程序流程圖3和IRQ3_KEY喚醒程序的部分代碼。
圖3 程序流程圖
R1=0x0000； //設置A口為帶下拉電阻的輸入口
[P_IOA_Attrib]=R1； //設置3個屬性向量
[P_IOA_Dir]=R1；
[P_IOA_Data]=R1； //中斷設置(允許IRQ3_KEY觸鍵中斷)
INT OFF； //關中斷
R1=0x0080； //設置中斷標置
[P_Int_Ctrl]=R1；
INT IRQ； //開中斷
//讀P_IOA_Latch單元，以鎖存IOA[0～7]的數據，用于觸鍵喚醒
R1=[P_IOA_Latch]； //鎖存A口低8位的數據
//將P_SystemClock(寫)7013H單元的第0~2位置為“111”，使系統進入睡眠狀態，
R1=0x0007； //系統進入睡眠狀態
[P_SystemClock]=R1；
//IRQ3子程序(端口A的觸鍵喚醒源被觸發后，調用IRQ3 中斷服務子程序)：
.TEXT
.PUBLIC _IRQ3
_IRQ3:
R1 = 0x0100； //比較是否為L_IRQ3_Ext1中斷
TEST R1,[P_INT_Ctrl]；
JNZ L_IRQ3_Ext1； //是，則進入；否，進行下面的判斷
R1 = 0x0200；
TEST R1,[P_INT_Ctrl]； //是否為L_IRQ3_Ext2中斷
JNZ L_IRQ3_Ext2； //是，進入該中斷；否，執行下面的程序
L_IRQ3_KeyChange_WakeUp: //不是上面的兩種中斷則一定為鍵喚醒中斷
R1 = 0x0080； //清除IRQ3觸鍵中斷請求
[P_INT_Clear]= R1；
:
(處理系統被喚醒后的任務)
:
RETI
L_IRQ3_Ext2:
[P_INT_Clear] = R1； //清除IRQ3_EXT2中斷請求
RETI
L_IRQ3_Ext1:
[P_INT_Clear] = R1； //清除IRQ3_EXT1中斷請求
RETI
相對于其它指紋識別系統控制核心大多數是DSP運算能力強，但控制能力差的缺點，本系統最大的創新點是控制核心采用了既具有單片機的控制功能，又具有強大的DSP運算能力于一體的16位SOC芯片SPCE061A，使本系統在進行簡單的擴展后即可以在指紋鎖、無鑰汽車、PDA設備、大型門禁系統等各種需要指紋控制的領域進行廣泛的應用。