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Fancy Figuring Ferrets Out Fake Photos
想要辨别假照片
Marilyn Monroe riding a T. Rex on the moon? Sure. All it takes is a little photo editing software.
玛丽莲梦露在月球上骑着霸王龙？当然可能。只需要用一个小小的图片编辑软件就能做到。
One of the most effective ways to spot less obvious fakes is to look at the shadows cast by objects in the picture. If they’re pointing in different directions, chances are the image you’re looking at isn’t real. But the analysis can be challenging when the objects have complex shapes and the shadows are cast on uneven surfaces.
辨别比较逼真的假照片最有效率的方法之一就是看图片中各个物体的阴影方向。如果物体阴影指向不同方向，那么这张照片八成是假的。但是当物体形状复杂，阴影照在不平的表面上的时候分析起来就有点困难了。
That’s why Dartmouth and UC Berkeley researchers have developed software that analyzes images on two fronts. The program tracks the shapes and angles of different shadows for inconsistencies. It also uses geometric algorithms to determine the angle of illumination on each object, which should match up if there’s a single light source. This research appears in the journal ACM Transactions on Graphics.
这就是达特茅斯大学和加州大学伯克利分校的研究人员开发从两个面分析图像的软件的原因。该程序追踪不同阴影形状和角度的一致性。它还能利用几何算法确定灯光照到每个物体的角度，如果是单光源的话，角度应该是一致的。这项研究发表在ACM Transactions on Graphics期刊上。
The researchers tested their software on a 1969 moon-landing photo. Conspiracy theorists often point to the complex orientation of shadows in the picture as evidence it was doctored. But the computer analysis says it’s kosher. Looks like we might have made it to the moon after all.
研究人员用一张1969年登陆月球的照片测试了他们的软件。阴谋论者总是说这张阴影取向复杂的照片是伪造的。但是计算机分析显示这张图是真的。看来我们真的登录了月球。
—Larry Greenemeier
