Pictures like fig.1 are called "stereograms". In this text, I would like to explain why stereograms look 3D.

像图1这样的图片叫做“立体图”，在这篇文章中，我将向你解释为什么立体图看起来有3D的效果。

youdao

Please look hard at fig.1 once more, and you can find similar patterned repetitions in the horizontal direction. This is a key point.

请再一次努力的看下立体图1，你可以看到水平方向上有反复的相似图案，这就是关键。

youdao

Citigroup's Richard Gardner: On purely a hardware spec basis, the iPad 2 allows Apple to catch up or exceed competitors' current features (see fig.1).

花旗银行(Citigroup)的理查德·加德纳：仅仅从硬件参数来看，苹果iPad 2就已赶上或超越其它竞争对手目前的产品。

youdao

The CO2 reduction takes place on a metal catalyst at the opposite side of nitride semiconductor photo-electrode.(See Fig. 1) The metal catalyst plays an important role in selecting and accelerating the reaction.

ENGADGET: Panasonic Photosynthesis System converts carbon dioxide to organic material with plant-like efficiency