首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
The Evolution of the Photofit Security technology: A new type of computerised photofit system takes a novel evolutionary app
The Evolution of the Photofit Security technology: A new type of computerised photofit system takes a novel evolutionary app
admin
2011-01-15
90
问题
The Evolution of the Photofit
Security technology: A new type of computerised photofit system takes a novel evolutionary approach to generating images of suspects. If you have ever tried to describe someone’s face in detail, you will understand why the "photofit" composite images used by the police look so dodgy. In recent years, computerised "E-Fit" systems have helped improve the accuracy of these images by allowing witnesses to choose from a wider range of facial features. But researchers at the University of Stirling in Scotland found that, despite these improvements, people still have a hard time constructing recognisable faces--especially if there is a delay of more
The problem is that people tend to recoguise faces as whole entities, rather than as separate features. So picking from a range of eyes, noses and mouths is not necessarily the most suitable approach, says Charlie Frowd, a psychologist at the University of Stifling. Next year, however, British police are expected to begin trials of a new computerised system, called EvoFIT, developed by Dr. Frowd and his colleague Peter Hancock. It uses an evolutionary approach, known as a genetic algorithm, to "evolve" faces rather than piece them together.
"The process is entirely non-verbal and takes a fraction of the normal time," claims Dr. Frowd. A witness is shown an array of 60 different faces with random features. Having studied them closely, the witness is asked to choose the six images that most closely resemble the person they are trying to describe. These six are then used to generate another set of 60, by switching featurees between some of the images and by making random changes to others. The witness is then asked to repeat the task, whereupon a new batch of faces is generated, and so on. In evolutionary terms, this process is known as "genetic crossover and mutation", and is a powerful way to search a large number of possibilities for a particular solution. By allowing the user to steer the selection process, the program is able to generate a good likeness for the original face after just a few cycles.
In one of its early versions, EvoFIT was used by police in Northampton shire who were trying to catch a violent attacker. The attacker was never caught, but the senior investigating officer, Superintendent Paul Spick, says the witness involved found the new software much quicker and easier to use than traditional E-Fit systems. It was also more accurate: the final image caused the witness visible distress when displayed. A further important advantage of EvoFIT over traditional composites is that an image can be generated even if the witness can only provide a sketchy verbal description.
The researchers have since made a number of further improvements to their system and are now in the process of commercializing it in partnership with ABM, a British firm which supplies police forces with photofit, one of the leading computerized composite systems. The images are more realistic, and the system can generate three-quarter angle views of the face, which are easier to distinguish than direct frontal views, says Dr. Frowd.
A His team has also found that by combining the images generated by different witnesses, or even from a single witness, it is possible to get an even better likeness. B This could be particularly useful when multiple witnesses come forward and the police are unsure which of the images they produce is the most accurate. C In the latest version, witnesses are given a selection of face shapes to choose from before facial features are added. D This makes it less likely that the correct facial features will be rejected simply because they are on the wrong-shaped face.
These modifications appear to make all the difference. In recent experiments, Dr. Frowd and Dr. Hancock compared EvoFIT with the computerized systems currently in use by asking volunteers to construct an image of a face two days after seeing it, and then showing the resulting image to people who were familiar with the person depicted. With traditional composites, the person was correctly identified about 4% of the time; the figure rose to 25% with EvoFIT images.
Next year ABM will perform inhouse evaluations of the system and will then team up with police forces for further trials. Although things look promising so far, two things in particular need further testing, says Leslie Bowie, ABM’s director of research. Do the EvoFIT images distract witnesses or contaminate their memories of the face they are trying to recall? And while EvoFIT has performed well in the calm conditions of the laboratory, how will it cope with real-life witnesses, who are often traumatized by their experiences? If it can address these two questions, EvoFIT could be the next step in the evolution of the photofit.
According to the passage, Which of the following is true?
选项
A、Faces are more often to be remembered as whole entities.
B、Faces are not likely to be remembered as whole entities.
C、Faces are more likely to be recognized.
D、It can piece the facial features together based on witnesses’ descriptions.
答案
A
解析
转载请注明原文地址:https://kaotiyun.com/show/k2yO777K
0
托福(TOEFL)
相关试题推荐
MorseCodeMorsecodeisbeingreplacedbyanewsatellite-basedsystemforsendingdistresscallsatsea.Itsdotsanddashesh
MorseCodeMorsecodeisbeingreplacedbyanewsatellite-basedsystemforsendingdistresscallsatsea.Itsdotsanddashesh
ClassifythefollowinginformationasreferringtoAadoptedthewritingsystemfromanothercountryBusedorganicmaterialst
ClassifythefollowinginformationasreferringtoAadoptedthewritingsystemfromanothercountryBusedorganicmaterialst
ClassifythefollowinginformationasreferringtoAadoptedthewritingsystemfromanothercountryBusedorganicmaterialst
TheEvolutionaryMystery:CrocodileSurvivesA.Eventhoughcrocodileshaveexistedfor200millionyears,they’reanything
TheEvolutionaryMystery:CrocodileSurvivesA.Eventhoughcrocodileshaveexistedfor200millionyears,they’reanything
随机试题
人不难以死免其君,我戮之不祥。难:
关于肺癌的叙述,不正确的是
一患儿以中毒性脑病入院,突然护士观察病情时发现呼吸不规则,意识障碍加重,瞳孔不等大光反射减弱,护士此时应采取的首要的措施是
《物业管理条例》确立的基本制度包括()。
建设工程实施过程中投入的生产要素包括( )。
间接成本是指与成本对象相关联的成本中()。
[*]
一棵二叉树中共有70个叶子结点与80个度为1的结点,则该二叉树中的总结点数为
24,30,?,60,84,114Whatnumbershouldreplacethequestionmark?
Nextyear,ifallgoesasplanned,thelargestmakerofpersonalcomputersinAsiawillbecomethethirdlargestintheworld.
最新回复
(
0
)