VOA标准英语2008年-Scientists Develop Reliable Face Recognition Sy

By Jessica Berman
Washington
24 January 2008

Researchers say they have improved the accuracy of automatic face recognition systems, which are being used more and more by crime prevention and national security agencies. The investigators¹ have created what they call an "average face" that, they say, allows the machines to make a correct identification in every case. VOA's Jessica Berman explains.

Experts say that automatic face recognition systems, in which a computer attempts to recognize an individual by checking his or her face against thousands of images stored in a database, are gaining in popularity, but are not very reliable.

There won't be a match if the person's face is not contained in the database, or a match may be overlooked if a picture that is in the database looks sufficiently² different than the individual standing³ in front of the system's electronic eye.

Experts say that's because the stored photograph may be several years old and bear little resemblence to the individual, or the pose or light may be different.

Psychologist Rob Jenkins of the University of Glascow and his colleague Mike Burton believe they solved the problem.

They randomly⁴ gathered 20 images of 25 famous male celebrities⁵ on the internet and fed the photos into a face recognition system that had a database of 31-thousand photos of famous faces.

The recognition system accurately⁶ identified the individuals about half of the time .

The researchers then created what they call an "average face" of each celebrity⁷ by taking his images and averaging them out. They did that by removing "unhelpful" aspects of the images, such as lighting⁸ effects, and highlighting structural⁹ features of the face, Jenkins said.

"So, what we were able to show is that if you take these highly variable images, and apply the averaging process to them, then the recognition performance goes right up. In the study we reported, it goes from 54 percent, which is the performance that it got on standard photographs, up to 100 percent. So it's a really huge leap," she said.

Jenkins sees no reason why "average face" photos could not be made of everyone and used for identification purposes. He says the average faces could also be used with existing face recognition technology for use, say, at airport check points.

To be sure, the Scottish psychologist is ready. He made an "average face" image of himself using 20 different images. "What's striking to me is how bad a likeness¹⁰ my passport photo is and how a good a likeness the average image is. Certainly, think if I were at customs deciding whether to admit myself or not, I think I would have to say 'no,'" he said.

Jenkins and Burton report their work in the journal Science.

1 investigators   

n.调查者，审查者( investigator的名词复数 )

参考例句：

• This memo could be the smoking gun that investigators have been looking for. 这份备忘录可能是调查人员一直在寻找的证据。
• The team consisted of six investigators and two secretaries. 这个团队由六个调查人员和两个秘书组成。 来自《简明英汉词典》

2 sufficiently   

adv.足够地，充分地

参考例句：

• It turned out he had not insured the house sufficiently.原来他没有给房屋投足保险。
• The new policy was sufficiently elastic to accommodate both views.新政策充分灵活地适用两种观点。

3 standing   

n.持续，地位；adj.永久的，不动的，直立的，不流动的

参考例句：

• After the earthquake only a few houses were left standing.地震过后只有几幢房屋还立着。
• They're standing out against any change in the law.他们坚决反对对法律做任何修改。

4 randomly   

adv.随便地，未加计划地

参考例句：

• Within the hot gas chamber, molecules are moving randomly in all directions. 在灼热的气体燃烧室内，分子在各个方向上作无规运动。 来自辞典例句
• Transformed cells are loosely attached, rounded and randomly oriented. 转化细胞则不大贴壁、圆缩并呈杂乱分布。 来自辞典例句

5 celebrities   

n.（尤指娱乐界的）名人( celebrity的名词复数 )；名流；名声；名誉

参考例句：

• He only invited A-list celebrities to his parties. 他只邀请头等名流参加他的聚会。
• a TV chat show full of B-list celebrities 由众多二流人物参加的电视访谈节目

6 accurately   

adv.准确地，精确地

参考例句：

• It is hard to hit the ball accurately.准确地击中球很难。
• Now scientists can forecast the weather accurately.现在科学家们能准确地预报天气。

7 celebrity   

n.名人，名流；著名，名声，名望

参考例句：

• Tom found himself something of a celebrity. 汤姆意识到自己已小有名气了。
• He haunted famous men, hoping to get celebrity for himself. 他常和名人在一起, 希望借此使自己获得名气。

8 lighting   

n.照明，光线的明暗，舞台灯光

参考例句：

• The gas lamp gradually lost ground to electric lighting.煤气灯逐渐为电灯所代替。
• The lighting in that restaurant is soft and romantic.那个餐馆照明柔和而且浪漫。

9 structural   

adj.构造的，组织的，建筑（用）的

参考例句：

• The storm caused no structural damage.风暴没有造成建筑结构方面的破坏。
• The North American continent is made up of three great structural entities.北美大陆是由三个构造单元组成的。

10 likeness   

n.相像，相似（之处）

参考例句：

• I think the painter has produced a very true likeness.我认为这位画家画得非常逼真。
• She treasured the painted likeness of her son.她珍藏她儿子的画像。