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ASCII立体图
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ASCII立体图（ASCII stereogram），是ASCII艺术的一种形式，它利用观察图像时，令视线产生适当的交叉从而生成三维图像的错视。_NEWLINE_以图1为例，为了得到三维效果，观察者需要使眼睛偏离聚焦状态，这样同一行中的两个相邻字符就会贴近到一起。为了帮助聚焦，努力使两个顶上的两个大写字母O 看起来像三个，确保中间那个O 的图像稳定并且位于焦点之上。一旦做到了这一点，往下看下面的图像，这时三维效果就很明显了：7列字母会呈现远近相间的视觉效果。如果图1 底部的两个O 看起来像三个，那么远近效果就会相反。另外也可以通过视线交叉观察到相反的三维效果。_NEWLINE__NEWLINE_                             O    O_NEWLINE_n   n   n   n   n   n   n   n   n   n   n   n   n   n   n   n   n_NEWLINE_f    f    f    f    f    f    f    f    f    f    f    f    f    f_NEWLINE_e   e   e   e   e   e   e   e   e   e   e   e   e   e   e   e   e_NEWLINE_a    a    a    a    a    a    a    a    a    a    a    a    a    a_NEWLINE_a   a   a   a   a   a   a   a   a   a   a   a   a   a   a   a   a_NEWLINE_r    r    r    r    r    r    r    r    r    r    r    r    r    r_NEWLINE_r   r   r   r   r   r   r   r   r   r   r   r   r   r   r   r   r_NEWLINE_                          O          O  _NEWLINE_图 2 的效果更加有戏剧性。一旦看到了三维效果，观察者渐渐远离屏幕，垂直线将会变得更深，因而增加立体效果，水平或者竖直方向稍微移动也会产生有趣的效果。_NEWLINE__NEWLINE_                           O          O_NEWLINE_.  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  ._NEWLINE_ .   .   .   .   .   .   .   .   .   .   .   .   .   .   .   .   ._NEWLINE_   .    .    .    .    .    .    .    .    .    .    .    .    ._NEWLINE_   .     .     .     .     .     .     .     .     .     .     ._NEWLINE_     .      .      .      .      .      .      .      .      ._NEWLINE_ .       .       .       .       .       .       .       .       ._NEWLINE_      .        .        .        .        .        .        ._NEWLINE_   .         .         .         .         .         .         ._NEWLINE_.          .          .          .          .          .          ._NEWLINE_|          |          |          |          |          |          |_NEWLINE_|          |          |          |          |          |          |_NEWLINE_|          |          |          |          |          |          |_NEWLINE_|          |          |          |          |          |          |_NEWLINE_|          |          |          |          |          |          |_NEWLINE_|          |          |          |          |          |          |_NEWLINE_   .         .         .         .         .         .         ._NEWLINE_      .        .        .        .        .        .        ._NEWLINE_ .       .       .       .       .       .       .       .       ._NEWLINE_     .      .      .      .      .      .      .      .      ._NEWLINE_   .     .     .     .     .     .     .     .     .     .     ._NEWLINE_   .    .    .    .    .    .    .    .    .    .    .    .    ._NEWLINE_ .   .   .   .   .   .   .   .   .   .   .   .   .   .   .   .   ._NEWLINE_.  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  ._NEWLINE_图 3 根据与单图像随机点立体图（Single Image Random Dot Stereogram，简称 SIRDS）同样的思想显示了一个单图像随机文本立体图（Single Image Random Text Stereogram，简称 SIRTS）。当立体图像变得清楚的时候就可以看到浮雕中的“Hi”。_NEWLINE__NEWLINE_                      O              O_NEWLINE_OIWEQPOISDFBKJFOIWEQPOISDFBKJFOIWEQPOISDFBKJFOIWEQPOISDFBKJF_NEWLINE_EDGHOUIEROUIYWEVDGHOXUIEROIYWEVDGHEOXUIEOIYWEVDGHEOXUIEOIYWE_NEWLINE_KJBSVDBOIWERTBAKJBSVEDBOIWRTBAKJBSOVEDBOWRTBAKJBSOVEDBOWRTBA_NEWLINE_SFDHNWECTBYUVRGSFDHNYWECTBUVRGSFDHCNYWECBUVRGSFDHCNYWECBUVRG_NEWLINE_HNOWFHLSFDGWVRGHNOWFGHLSFDWVRGHNOWSFGHLSDWVRGHNLOWSFGLSDWVRG_NEWLINE_YPOWVXTNWFECHRGYPOWVEXTNWFCHRGYPOWNVEXTNFCHRGYPWOWNVETNFCHRG_NEWLINE_SVYUWXRGTWVETUISVYUWVXRGTWVETUISVYUWVXRGWVETUISVYUWVXRGWVETU_NEWLINE_WVERBYOIAWEYUIVWVERBEYOIAWEYUIVWVERBEYOIWEYUIVWLVERBEOIWEYUI_NEWLINE_EUIOETOUINWEBYOEUIOEWTOUINWEBYOEUIOEWTOUNWEBYOETUIOEWOUNWEBY_NEWLINE_WFVEWVETN9PUW4TWFVEWPVETN9UW4TWFVETWPVET9UW4TWFBVETWPET9UW4T_NEWLINE_NOUWQERFECHIBYWNOUWQXERFECIBYWNOUWFQXERFCIBYWNOFUWFQXRFCIBYW_NEWLINE_VEHWETUQECRFVE[VEHWERTUQECFVE[VEHWQERTUQCFVE[VEOHWQERUQCFVE[_NEWLINE_UIWTUIRTWUYWQCRUIWTUYIRTWUWQCRUIWTXUYIRTUWQCRUIBWTXUYRTUWQCR_NEWLINE_IYPOWOXNPWTHIECIYPOWTOXNPWHIECIYPONWTOXNWHIECIYLPONWTXNWHIEC_NEWLINE_R9UHWVETPUNRQYBR9UHWVETPUNRQYBR9UHWVETPUNRQYBR9UHWVETPUNRQYB_NEWLINE_有人在电子邮件末尾或者新闻文章后面用立体图作为“签名”，图 4 就是一个这样的例子。_NEWLINE__NEWLINE_ IIIIIIIIIIIIIII   IIIIIIIIIIIIIII  _NEWLINE_ H ( )  \|/    H   H   ( )   \|/ H  _NEWLINE_ H(   ) -O-    H   H  (   )  -O- H  _NEWLINE_ H     )/|\    H   H (     ) /|\ H  _NEWLINE_ H======^======H   H======^======H  _NEWLINE_ H- |----@-----H   H----| ---@---H  _NEWLINE_ H /|\ @\|/ @  H   H   /|\@ \|/@ H _NEWLINE_ H    \|/  \|/ H   H     \|/  \|/H  _NEWLINE_ III^IIIIIII^III   III^IIIIIII^III  _NEWLINE_Wide eyed stereo  Wide  eyed  stereo    _NEWLINE_立体效果可以用于突出文本中的单个字词作为“秘密消息”，当段落调整的时候这个效果可能就被隐藏起来。_NEWLINE_According    to    the  According    to    the_NEWLINE_police      inspector,  police      inspector,_NEWLINE_Edward  John Billings,  Edward John  Billings,_NEWLINE_there  are   too  many  there  are   too  many_NEWLINE_individuals  too close  individuals  too close_NEWLINE_to  the  case to  make  to  the  case to  make_NEWLINE_an  arrest.   I  asked  an  arrest.   I  asked_NEWLINE_Mary  Smith to comment  Mary Smith  to comment_NEWLINE_on  the case,  but she  on  the case,  but she_NEWLINE_declined  to  comment,  declined  to  comment,_NEWLINE_because  she  is  soon  because  she is   soon_NEWLINE_to   be   married   to  to   be   married   to_NEWLINE_Howard  D. Fredericks,  Howard  D. Fredericks,_NEWLINE_the   victim's  uncle.  the   victim's  uncle._NEWLINE_Charles   Wilson,  the  Charles   Wilson,  the_NEWLINE_victim's      brother,  victim's      brother,_NEWLINE_stated that  the chaos  stated that  the chaos_NEWLINE_was   responsible  for  was  responsible   for_NEWLINE_at least  five suicide  at least  five suicide_NEWLINE_attempts   last   week  attempts   last   week_NEWLINE_alone.                  alone.                               _NEWLINE_另外也可以实现ASCII 立体图动画。
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致谢
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图 1、2、3 与 4 分别归属于David B. Thomas、Jonathan Bowen、Charles Durst 与 Marty Hewes。这四幅立体图出现在公开的alt.3d USENET 新闻组 中。图 5 是一位维基人现场作出来的。_NEWLINE_最初由ASCII Stereograms 的作者改编而来，并且得到了作者的许可。