ASCII立體圖（en:ASCII stereogram）是ASCII藝術的一種形式，它用一幅圖像或者一對相鄰的圖像使眼睛產生適當的交叉從而生成三維圖像的錯視。
基本介紹
- 中文名：ASCII立體圖
- 外文名：en:ASCII stereogram
- 性質：ASCII藝術的一種形式
- 特點：觀察者需要使眼睛偏離聚焦狀態
以圖 1 為例，為了得到三維效果，觀察者需要使眼睛偏離聚焦狀態，這樣同一行中的兩個相鄰字元就會貼近到一起。為了幫助聚焦，努力使兩個頂上的兩個大寫字母 O 看起來像三個，確保中間那個 O 的圖像穩定並且位於焦點之上。一旦做到了這一點，往下看下面的圖像，這時三維效果就很明顯了。如果圖 1 底部的兩個 O 看起來像三個，那么效果就會倒退回來。另外也可以通過視線交叉觀察到相反的三維效果，但是這做起來更加困難。
------------------------------------------------ 圖 1: 遠近距離
O O
n n n n n n n n n n n n n n n n n
f f f f f f f f f f f f f f
e e e e e e e e e e e e e e e e e
a a a a a a a a a a a a a a
a a a a a a a a a a a a a a a a a
r r r r r r r r r r r r r r
r r r r r r r r r r r r r r r r r
-------------------------------- 圖 2 的效果更加有戲劇性。一旦看到了三維效果，觀察者漸漸遠離螢幕將會逐漸增加立體效果，水平或者豎直方向稍微移動也會產生有趣的效果。
圖 3 根據與單圖像隨機點立體圖（Single Image Random Dot Stereogram，簡稱 SIRDS）同樣的思想顯示了一個 單圖像隨機文本立體圖（Single Image Random Text Stereogram，簡稱 SIRTS）。當立體圖像變得清楚的時候就可以看到浮雕中的“Hi”。
有人在電子郵件末尾或者新聞文章後面用立體圖作為“簽名”，圖 4 就是一個這樣的例子。
----------------------------------圖 2: 地板、牆壁與天花板
OO
. . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . .
. . . . . . . . . . . . .
. . . . . . . . . . .
. . . . . . . . .
. . . . . . . . .
. . . . . . .
.......
.......
|||||||
|||||||
|||||||
|||||||
|||||||
|||||||
.......
. . . . . . .
. . . . . . . . .
. . . . . . . . .
. . . . . . . . . . .
. . . . . . . . . . . . .
. . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . .
-------------------------------圖 3: A single image random text stereogram.
O O
OIWEQPOISDFBKJFOIWEQPOISDFBKJFOIWEQPOISDFBKJFOIWEQPOISDFBKJF
EDGHOUIEROUIYWEVDGHOXUIEROIYWEVDGHEOXUIEOIYWEVDGHEOXUIEOIYWE
KJBSVDBOIWERTBAKJBSVEDBOIWRTBAKJBSOVEDBOWRTBAKJBSOVEDBOWRTBA
SFDHNWECTBYUVRGSFDHNYWECTBUVRGSFDHCNYWECBUVRGSFDHCNYWECBUVRG
HNOWFHLSFDGWVRGHNOWFGHLSFDWVRGHNOWSFGHLSDWVRGHNLOWSFGLSDWVRG
YPOWVXTNWFECHRGYPOWVEXTNWFCHRGYPOWNVEXTNFCHRGYPWOWNVETNFCHRG
SVYUWXRGTWVETUISVYUWVXRGTWVETUISVYUWVXRGWVETUISVYUWVXRGWVETU
WVERBYOIAWEYUIVWVERBEYOIAWEYUIVWVERBEYOIWEYUIVWLVERBEOIWEYUI
EUIOETOUINWEBYOEUIOEWTOUINWEBYOEUIOEWTOUNWEBYOETUIOEWOUNWEBY
WFVEWVETN9PUW4TWFVEWPVETN9UW4TWFVETWPVET9UW4TWFBVETWPET9UW4T
NOUWQERFECHIBYWNOUWQXERFECIBYWNOUWFQXERFCIBYWNOFUWFQXRFCIBYW
VEHWETUQECRFVE[VEHWERTUQECFVE[VEHWQERTUQCFVE[VEOHWQERUQCFVE[
UIWTUIRTWUYWQCRUIWTUYIRTWUWQCRUIWTXUYIRTUWQCRUIBWTXUYRTUWQCR
IYPOWOXNPWTHIECIYPOWTOXNPWHIECIYPONWTOXNWHIECIYLPONWTXNWHIEC
R9UHWVETPUNRQYBR9UHWVETPUNRQYBR9UHWVETPUNRQYBR9UHWVETPUNRQYB
---------------------------------------圖 4: 一個立體圖簽名
IIIIIIIIIIIIIII IIIIIIIIIIIIIII
H ( ) \|/ H H ( ) \|/ H
H( ) -O- H H ( ) -O- H
H )/|\ H H ( ) /|\ H
H======^======H H======^======H
H- |----@-----H H----| ---@---H
H /|\ @\|/ @ H H /|\@ \|/@ H
H \|/ \|/ H H \|/ \|/H
III^IIIIIII^III III^IIIIIII^III
Wide eyed stereo Wide eyed stereo
立體效果可以用於突出文本中的單個字詞作為“秘密訊息”，當段落調整的時候這個效果可能就被隱藏起來。
圖 5: 單詞強調
According to the police inspector, According to the police inspector,
Edward John Billings, there are Edward John Billings, there are
too many individuals too close to too many individuals too close to
the case to make an arrest. I asked the case to make an arrest. I asked
Mary Smith to comment on the case, Mary Smith to comment on the case,
but she declined to comment, on the but she declined to comment, on the
grounds that she is engaged to be grounds that she is engaged to be
married to Howard Fredericks, the married to Howard Fredericks, the
victim's uncle. Charles Wilson, victim's uncle. Charles Wilson,
the victim's brother, stated that the victim's brother, stated that
the chaos was responsible for at the chaos was responsible for at
least five suicide attempts last least five suicide attempts last
week alone. week alone.
另外也可以實現 ASCII 立體圖動畫。
