The speckle is a scattering of light caused by micron-sized ridges and groves on an object 's surface .
这种散斑来源于光散射效应在物体表面产生的微米大小的隆起和沟痕。
Variations in the speckle are then digitised to produce a code that is unique to the scanned item .
对于每一个被扫描的物体，散斑的变化信息会被数字化，然后生成一个独特代码。
The process was developed initially at imperial college , london , and is based on a phenomenon known as laser speckle .
该项工艺最初由伦敦帝国理工学院研发，它是基于一种称作激光散斑的物理现象。
This is because , during the original scan , the detectors pick up such a large amount of information that a re-scan need provide only part of the speckle pattern for a reliable comparison to be made .
