Recognise Stack Exchange Sites by Their Icon
C#, 2760 bytes
namespace System{class P{static void Main(){var c="us>g System;us>g System.Draw>g;class p{publ' stZ' void c(){var b=(Bitmap)Bitmap.FromFile(Console.ReadL>e());Console.Write(!1,1[3,3#2?!4,4#1?!5,5#2?!@#1?!+$SupK UsK*Salesforce%]^$< F't~_Fantasy%8,8#6?$Arqade*Ask Ubuntu%@#6?$WordPress Development%8,8#4?!9,9#2?$Phys's*UsK ExpKience%+$Travel*Craft CMS%5,5^!@#6?!]#1?$TeX - LaTeX%+$Mi Yodeya*Meta Stack Exchange%]#6?$ProgrammK|2,2#5?$Christianity*MZhemZ'a%@[]^$MZhemZ'|0,0#1?$Cross ValidZed*Theoret'al ComputK <%2,2^!]#5?$Seasoned Adv'e*Drupal AnswK|]^$Graph' Design*WebmastK|2,2^!4,4#5?!5,5#2?!@^$Ask PZents*Home Improvement%@#6?$Android Enthusiasts*Skept'|5,5#4?!@#5?$Web Appl'Z~s*English/_Usage%@#4?!]#8?$SharePo>t*B'ycle|]#1?$Electr'al Eng>eK>g*DZabase Adm>istrZor|4,4^!5,5#2?!+$Game Development*Photography%@:SKvK Fault%+$Geograph' InformZ~ Systems*Unix_L>ux%5,5^!0`Stack Apps*The Workplace%+!@[]#4?$InformZ~ Security*Ask DiffKent%]:Role-play>g Games*PKsonal F>ance_Money%3,9#8?$Academia%5,15^$& > Japanese%0,13:&*& > Portuguese%2,2:MZhOvKflow%3,3:AviZ~%4,4^$LEGO AnswK|5,5[@[][0,1:PokK*Anime_Manga%+$BlendK*H>duism%][8,8:WritK|0,1^!2`RaspbKry Pi*W>dows Phone%+$Biology*Worldbuild>g%9,9:Movies_TV%8,8[6`Trid~*Islam%0,1:Mus', Pract'e_Theory*L>guist'|][@[9,9:Ches|+!4,6:Garden>g_Landscap>g*Susta>able Liv>g%4,6:Buddhism*Startup|8,8:English/ LearnK|3,4[6,7:Network Eng>eK>g%9,5:Magento%+$Motor Veh'le Ma>tenance_Repair*MZhemZ's EducZor|4,8:GKman/%7`Joomla%7,6[+$QuantitZive F>ance*Ardu>o%9`Chemistry*Cryptography%8,8[0,1^!@[3`Tor%4,5:French/*The GreZ Outdoor|3`Project Management%3,6:Ch>ese/*Space ExplorZ~%+!2,6:Programm>g Puzzles_Code Golf%@:Cognitive <s*Signal Process>g%1,0:Ebook|@[4,5:Earth <*BeK%8,5:Emacs*ExpZriZe|1`History of < and MZh%3,4[@[+$Homebrew>g%3,6:DZa <*Video Product~%5,7:Russian/%9,4[4,8:Bibl'al HKmeneut's*Philosophy%11,6:Board_Card Games*Bitco>%3,5[@[3,8:AmZeur Radio%5,6:Genealogy_Family History%6,9:Software Quality Assurance_Test>g*Open DZa%3,6[11,7:Code Review%+$ComputK <*Community Build>g%10,6[+$Sports*Software RecommendZ~|9`Sound Design*ComputZ~al <%3,7:Japanese/%5,8[7,5:Puzzl>g%8,5:Econom's*Express~Eng>e AnswK|6,5[9,4[7`Freelanc>g*History%10,6:Italian/%6`Parent>g*Astronomy%6,7[9`RevKse Eng>eK>g*Robot'|10,8[+$Polit's*Pet|12,5:PKsonal Productivity*Phys'al Fitness$);}}";foreach(var s in "~ion;|s%;`,4:;&Stack OvKflow;_ & ;^#3?;]7,7;'ic;['!;Zat;Ker;@6,6;>in;<Science;:'$;/ Language;+0,0#3?;*$:$;'#7?;%$:!;$\";#).B%9<;!b.GetPixel(".Split(';'))c=c.Replace(s[0]+"",s.Substring(1));new Microsoft.CSharp.CSharpCodeProvider().CompileAssemblyFromSource(new CodeDom.Compiler.CompilerParameters("mscorlib.dll System.Core.dll System.Drawing.dll".Split()),c).CompiledAssembly.CreateInstance("p").GetType().GetMethod("c").Invoke(c,null);}}}
My solution doesn't use hashing, it actually examines the individual pixels of the image and decides based on that. I discovered that it was enough to examine the blue component of the image modulo 9. The idea is to repeatedly split based on the value of pixel.B%9, like so:
b.GetPixel(3,4).B % 9 < 7 ? "Russian Language" : (b.GetPixel(8,4).B % 9 < 6 ? "Project Management" : "Philosophy")
Using a script, I generated the following monstrous program (5197 bytes) that solves the problem using a binary decision tree:
using System;using System.Drawing;class p {public static void c(){var b=(Bitmap)Bitmap.FromFile(Console.ReadLine());Console.Write(b.GetPixel(4,5).B%9<6?b.GetPixel(1,1).B%9<5?b.GetPixel(1,10).B%9<1?b.GetPixel(3,4).B%9<1?b.GetPixel(2,8).B%9<2?b.GetPixel(0,0).B%9<3?b.GetPixel(3,10).B%9<8?"Super User":"Travel":b.GetPixel(0,2).B%9<3?"Salesforce":"Craft CMS":b.GetPixel(2,4).B%9<2?b.GetPixel(2,2).B%9<6?"Ask Ubuntu":"Ask Different":b.GetPixel(1,3).B%9<6?"Mathematics":"Programmers":b.GetPixel(2,7).B%9<3?b.GetPixel(2,4).B%9<1?b.GetPixel(2,8).B%9<2?"Database Administrators":"Christianity":b.GetPixel(0,1).B%9<3?"TeX - LaTeX":"Game Development":b.GetPixel(1,6).B%9<3?b.GetPixel(2,3).B%9<7?"English Language & Usage":"Skeptics":b.GetPixel(0,0).B%9<3?"StackApps":"Unix & Linux":b.GetPixel(0,6).B%9<1?b.GetPixel(1,4).B%9<2?b.GetPixel(1,5).B%9<3?b.GetPixel(0,4).B%9<1?"Arqade":"Mi Yodeya":b.GetPixel(1,6).B%9<6?"Drupal Answers":"User Experience":b.GetPixel(1,5).B%9<4?b.GetPixel(1,6).B%9<3?"SharePoint":"Bicycles":b.GetPixel(0,0).B%9<3?"Home Improvement":"Photography":b.GetPixel(0,0).B%9<3?b.GetPixel(0,7).B%9<2?b.GetPixel(0,1).B%9<1?"Science Fiction & Fantasy":"Theoretical Computer Science":b.GetPixel(0,4).B%9<2?"Android Enthusiasts":"Ask Patents":b.GetPixel(5,15).B%9<3?b.GetPixel(2,0).B%9<3?"Meta Stack Exchange":"Stack Overflow inJapanese":b.GetPixel(0,13).B%9<7?"Stack Overflow":"Stack Overflow in Portuguese":b.GetPixel(5,8).B%9<7?b.GetPixel(4,4).B%9<7?b.GetPixel(0,0).B%9<3?b.GetPixel(7,5).B%9<7?b.GetPixel(0,1).B%9<5?"German Language":"Server Fault":b.GetPixel(8,5).B%9<7?"Economics":"ExpressionEngine Answers":b.GetPixel(1,13).B%9<7?b.GetPixel(0,1).B%9<7?"Ebooks":"MathOverflow":b.GetPixel(7,5).B%9<7?"Buddhism":"Earth Science":b.GetPixel(6,6).B%9<7?b.GetPixel(4,6).B%9<7?b.GetPixel(3,6).B%9<7?"Poker":"Gardening & Landscaping":b.GetPixel(0,0).B%9<3?"Sustainable Living":"Startups":b.GetPixel(7,6).B%9<7?b.GetPixel(0,0).B%9<3?"Quantitative Finance":"Arduino":b.GetPixel(9,4).B%9<7?"Chemistry":"Cryptography":b.GetPixel(5,4).B%9<7?b.GetPixel(9,5).B%9<7?b.GetPixel(10,8).B%9<7?b.GetPixel(0,0).B%9<3?"Reverse Engineering":"Pets":b.GetPixel(12,5).B%9<7?"Personal Productivity":"Physical Fitness":b.GetPixel(6,7).B%9<7?b.GetPixel(3,4).B%9<7?"Tor":"Robotics":b.GetPixel(7,5).B%9<7?"Politics":"French Language":b.GetPixel(0,1).B%9<3?b.GetPixel(9,5).B%9<7?b.GetPixel(3,4).B%9<3?"LEGO Answers":"Magento":b.GetPixel(6,5).B%9<7?"Motor Vehicle Maintenance & Repair":"Network Engineering":b.GetPixel(2,6).B%9<7?b.GetPixel(0,0).B%9<7?"Programming Puzzles & Code Golf":"History of Science and Math":b.GetPixel(0,2).B%9<7?"Mathematics Educators":b.GetPixel(1,4).B%9<7?"Signal Processing":"Cognitive Sciences":b.GetPixel(3,6).B%9<7?b.GetPixel(4,6).B%9<5?b.GetPixel(5,8).B%9<5?b.GetPixel(6,5).B%9<7?b.GetPixel(9,8).B%9<7?b.GetPixel(1,1).B%9<7?"Geographic Information Systems":"Biblical Hermeneutics":b.GetPixel(11,6).B%9<7?"Board & Card Games":"Bitcoin":b.GetPixel(0,0).B%9<3?b.GetPixel(2,4).B%9<7?"RaspberryPi":"English Language Learners":b.GetPixel(8,5).B%9<7?"Emacs":"Expatriates":b.GetPixel(5,4).B%9<6?b.GetPixel(6,8).B%9<7?b.GetPixel(3,4).B%9<7?"Russian Language":"Amateur Radio":b.GetPixel(8,4).B%9<7?"Project Management":"Philosophy":b.GetPixel(0,7).B%9<7?b.GetPixel(1,1).B%9<7?"Cross Validated":"Homebrewing":b.GetPixel(0,1).B%9<7?"Web Applications":"Biology":b.GetPixel(3,4).B%9<7?b.GetPixel(0,2).B%9<3?b.GetPixel(1,7).B%9<6?b.GetPixel(1,6).B%9<6?"WordPress Development":"Electrical Engineering":b.GetPixel(1,1).B%9<7?"Physics":"Windows Phone":b.GetPixel(1,0).B%9<7?b.GetPixel(0,0).B%9<3?"Webmasters":"Academia":b.GetPixel(3,8).B%9<7?"Data Science":"Worldbuilding":b.GetPixel(6,6).B%9<7?b.GetPixel(5,6).B%9<7?b.GetPixel(0,1).B%9<7?"Genealogy & Family History":"Anime & Manga":b.GetPixel(6,9).B%9<7?"Software Quality Assurance & Testing":"Open Data":b.GetPixel(9,4).B%9<7?b.GetPixel(0,0).B%9<3?"Code Review":"Community Building":b.GetPixel(8,4).B%9<7?"Chinese Language":"Computer Science":b.GetPixel(5,6).B%9<6?b.GetPixel(4,4).B%9<7?b.GetPixel(9,8).B%9<7?b.GetPixel(10,6).B%9<7?b.GetPixel(0,0).B%9<3?"Sports":"Software Recommendations":b.GetPixel(1,1).B%9<7?"Information Security":"Sound Design":b.GetPixel(3,5).B%9<7?b.GetPixel(8,4).B%9<7?"Space Exploration":"Computational Science":b.GetPixel(0,0).B%9<3?"Tridion":"Puzzling":b.GetPixel(0,5).B%9<3?b.GetPixel(6,8).B%9<7?b.GetPixel(5,8).B%9<7?"Blender":"Writers":b.GetPixel(6,5).B%9<7?"Music, Practice & Theory":"Islam":b.GetPixel(0,1).B%9<3?b.GetPixel(0,4).B%9<7?"Mathematica":"The Workplace":b.GetPixel(0,0).B%9<3?"Linguistics":"Hinduism":b.GetPixel(6,4).B%9<5?b.GetPixel(9,8).B%9<7?b.GetPixel(3,7).B%9<7?b.GetPixel(0,0).B%9<3?"Japanese Language":"Aviation":b.GetPixel(7,6).B%9<7?"History":"Italian Language":b.GetPixel(9,4).B%9<7?b.GetPixel(5,3).B%9<7?"Chess":"Freelancing":b.GetPixel(0,0).B%9<3?"Parenting":"Beer":b.GetPixel(0,5).B%9<1?b.GetPixel(4,8).B%9<7?b.GetPixel(1,1).B%9<7?"Role-playing Games":"Movies & TV":b.GetPixel(6,8).B%9<7?"Astronomy":"The Great Outdoors":b.GetPixel(0,4).B%9<3?b.GetPixel(0,6).B%9<7?"SeasonedAdvice":"Personal Finance & Money":b.GetPixel(0,0).B%9<3?"Graphic Design":b.GetPixel(3,4).B%9<7?"Video Production":"Joomla");}}
Some people have used built-in compression functions in their solutions. I made my own, writing a script that identifies common substrings and replaces them by single-character shorthands. The code is compressed to the following 2502 bye string:
us@g System;us@g System.Draw@g;class p {publ| st^| void c(){var b=(Bitmap)Bitmap.FromFile(Console.ReadL@e());Console.Write(!4,5#6?!1,1#5?!1,10#1?!3`#1?!2,8#2?*!3,10#8?$Sup] Us]+Travel~0,2_$Salesforce+Craft CMS~2`#2?!2,2#6?$Ask Ubuntu+Ask Diff]ent~1,3#6?$M^hem^|s+Programm]s~2,7_!2`#1?!2,8#2?$D^abase Adm@istr^ors+Christianity~0,1_$TeX - LaTeX+Game Development~1,6_!2,3[English/:Usage+Skept|s'*$StackApps+Unix:L@ux~0,6#1?!1`#2?!1,5_!0`#1?$Arqade+Mi Yodeya~1,6#6?$Drupal Answ]s+Us] Exp]ience~1,5#4?!1,6_$SharePo@t+B|ycles'*$Home Improvement+Photography'*!0,7#2?!0,1#1?$> F|tion:Fantasy+Theoret|al Comput] >~0`#2?$Android Enthusiasts+Ask P^ents~5,15_!2,0_$Meta Stack Exchange+Stack Ov]flow @Japanese~0,13[Stack Ov]flow+Stack Ov]flow @ Portuguese~5,8<4`%*!7,5<0,1#5?$G]man/+S]v] Fault~8,5[Econom|s+ExpressionEng@e Answ]s~1,13<0,1[Ebooks+M^hOv]flow~7,5[Buddhism+Earth >~6,6<4,6<3,6[Pok]+Garden@g:Landscap@g'*$Susta@able Liv@g+Startups~7,6%*$Quantit^ive F@ance+Ardu@o~9`[Chemistry+Cryptography~5`<9,5<10,8%*$Rev]se Eng@e]@g+Pets~12,5[P]sonal Productivity+Phys|al Fitness~6,7<3`[Tor+Robot|s~7,5[Polit|s+French/~0,1_!9,5<3`_$LEGO Answ]s+Magento~6,5[Motor Veh|le Ma@tenance:Repair+Network Eng@e]@g~2,6<0,0[Programm@g Puzzles:Code Golf+History of > and M^h~0,2[M^hem^|s Educ^ors~1`[Signal Process@g+Cognitive >s~3,6<4,6#5?!5,8#5?!6,5<9,8<1,1[Geograph| Inform^ion Systems+Bibl|al H]meneut|s~11,6[Board:Card Games+Bitco@'*!2`[Raspb]ryPi+English/ Learn]s~8,5[Emacs+Exp^ri^es~5`#6?!6,8<3`[Russian/+Am^eur Radio~8`[Project Management+Philosophy~0,7<1,1[Cross Valid^ed+Homebrew@g~0,1[Web Appl|^ions+Biology~3`<0,2_!1,7#6?!1,6#6?$WordPress Development+Electr|al Eng@e]@g~1,1[Phys|s+W@dows Phone~1,0%*$Webmast]s+Academia~3,8[D^a >+Worldbuild@g~6,6<5,6<0,1[Genealogy:Family History+Anime:Manga~6,9[Software Quality Assurance:Test@g+Open D^a~9`%*$Code Review+Community Build@g~8`[Ch@ese/+Comput] >~5,6#6?!4`<9,8<10,6%*$Sports+Software Recommend^ions~1,1[Inform^ion Security+Sound Design~3,5<8`[Space Explor^ion+Comput^ional >'*$Tridion+Puzzl@g~0,5_!6,8<5,8[Blend]+Writ]s~6,5[Mus|, Pract|e:Theory+Islam~0,1_!0`[M^hem^|a+The Workplace'*$L@guist|s+H@duism~6`#5?!9,8<3,7%*$Japanese/+Avi^ion~7,6[History+Italian/~9`<5,3[Chess+Freelanc@g'*$Parent@g+Be]~0,5#1?!4,8<1,1[Role-play@g Games+Movies:TV~6,8[Astronomy+The Gre^ Outdoors~0`_!0,6[SeasonedAdv|e+P]sonal F@ance:Money'*$Graph| Design~3`[Video Production+Joomla$);}}
The dictionary needed for decompression is just 108 bytes:
: & ;<%!;|ic;`,4;_#3?;^at;]er;[%$;@in;>Science;~'!;/Language;+'$;*!0,0#3?;'$:;%#7?;$\";#).B%9<;!b.GetPixel(
The dictionary uses semicolons as delimiter, and contains single characters followed by their decompression. So to decompress, ":" would first be replaced by " & ", then "<" by "%!", "|" by "ic", and so on. Decompression of a string c can be expressed in quite a concise way:
foreach (var s in "[dictionary]".Split(';')) c = c.Replace(s[0] + "", s.Substring(1));
Then, after decompression I use some reflection black-magic to compile the code on the fly and run it:
namespace System
{
using Collections.Generic;
using CodeDom.Compiler;
using Microsoft.CSharp;
using Linq;
using Reflection;
class P
{
static void Main()
{
var c = "us@g System;us@g System.Draw@g;class p {publ| st^| void c(){var b=(Bitmap)Bitmap.FromFile(Console.ReadL@e());Console.Write(!4,5#6?!1,1#5?!1,10#1?!3`#1?!2,8#2?*!3,10#8?$Sup] Us]+Travel~0,2_$Salesforce+Craft CMS~2`#2?!2,2#6?$Ask Ubuntu+Ask Diff]ent~1,3#6?$M^hem^|s+Programm]s~2,7_!2`#1?!2,8#2?$D^abase Adm@istr^ors+Christianity~0,1_$TeX - LaTeX+Game Development~1,6_!2,3[English/:Usage+Skept|s'*$StackApps+Unix:L@ux~0,6#1?!1`#2?!1,5_!0`#1?$Arqade+Mi Yodeya~1,6#6?$Drupal Answ]s+Us] Exp]ience~1,5#4?!1,6_$SharePo@t+B|ycles'*$Home Improvement+Photography'*!0,7#2?!0,1#1?$> F|tion:Fantasy+Theoret|al Comput] >~0`#2?$Android Enthusiasts+Ask P^ents~5,15_!2,0_$Meta Stack Exchange+Stack Ov]flow @Japanese~0,13[Stack Ov]flow+Stack Ov]flow @ Portuguese~5,8<4`%*!7,5<0,1#5?$G]man/+S]v] Fault~8,5[Econom|s+ExpressionEng@e Answ]s~1,13<0,1[Ebooks+M^hOv]flow~7,5[Buddhism+Earth >~6,6<4,6<3,6[Pok]+Garden@g:Landscap@g'*$Susta@able Liv@g+Startups~7,6%*$Quantit^ive F@ance+Ardu@o~9`[Chemistry+Cryptography~5`<9,5<10,8%*$Rev]se Eng@e]@g+Pets~12,5[P]sonal Productivity+Phys|al Fitness~6,7<3`[Tor+Robot|s~7,5[Polit|s+French/~0,1_!9,5<3`_$LEGO Answ]s+Magento~6,5[Motor Veh|le Ma@tenance:Repair+Network Eng@e]@g~2,6<0,0[Programm@g Puzzles:Code Golf+History of > and M^h~0,2[M^hem^|s Educ^ors~1`[Signal Process@g+Cognitive >s~3,6<4,6#5?!5,8#5?!6,5<9,8<1,1[Geograph| Inform^ion Systems+Bibl|al H]meneut|s~11,6[Board:Card Games+Bitco@'*!2`[Raspb]ryPi+English/ Learn]s~8,5[Emacs+Exp^ri^es~5`#6?!6,8<3`[Russian/+Am^eur Radio~8`[Project Management+Philosophy~0,7<1,1[Cross Valid^ed+Homebrew@g~0,1[Web Appl|^ions+Biology~3`<0,2_!1,7#6?!1,6#6?$WordPress Development+Electr|al Eng@e]@g~1,1[Phys|s+W@dows Phone~1,0%*$Webmast]s+Academia~3,8[D^a >+Worldbuild@g~6,6<5,6<0,1[Genealogy:Family History+Anime:Manga~6,9[Software Quality Assurance:Test@g+Open D^a~9`%*$Code Review+Community Build@g~8`[Ch@ese/+Comput] >~5,6#6?!4`<9,8<10,6%*$Sports+Software Recommend^ions~1,1[Inform^ion Security+Sound Design~3,5<8`[Space Explor^ion+Comput^ional >'*$Tridion+Puzzl@g~0,5_!6,8<5,8[Blend]+Writ]s~6,5[Mus|, Pract|e:Theory+Islam~0,1_!0`[M^hem^|a+The Workplace'*$L@guist|s+H@duism~6`#5?!9,8<3,7%*$Japanese/+Avi^ion~7,6[History+Italian/~9`<5,3[Chess+Freelanc@g'*$Parent@g+Be]~0,5#1?!4,8<1,1[Role-play@g Games+Movies:TV~6,8[Astronomy+The Gre^ Outdoors~0`_!0,6[SeasonedAdv|e+P]sonal F@ance:Money'*$Graph| Design~3`[Video Production+Joomla$);}}";
foreach (var s in ": & ;<%!;|ic;`,4;_#3?;^at;]er;[%$;@in;>Science;~'!;/ Language;+'$;*!0,0#3?;'$:;%#7?;$\";#).B%9<;!b.GetPixel(".Split(';')) c = c.Replace(s[0] + "", s.Substring(1));
var o = new CSharpCodeProvider().CompileAssemblyFromSource(new CompilerParameters("mscorlib.dll System.Core.dll System.Drawing.dll".Split()), c).CompiledAssembly.CreateInstance("p").GetType().GetMethod("c");
o.Invoke(o, null);
}
}
}
Note that the examples used here for explanation are slightly different from the one used in the 2876 byte solution.
Python 3.x + Pillow, 2301 1894 1878 bytes
import sys,re,zlib as z,base64,PIL.Image as i
print(re.search(str(z.adler32(i.open(sys.argv[1]).tobytes()[2::6])%2003)+'(\\D+)',z.decompress(base64.b85decode(b'c${Tc%XZ>86#NyfdNqBH<%b?iLI_EpFkwO-GfQC$tcfjoB$+h*^;0s?o$g*?uzgjxs%~BKif!C3zALZEU!&?wJd#-mqgS@p<P&+)AsV|c*52*C>U&(1_4w^urvvWJU8Bj;bvv4ia;eiJLu+bsXLru`DjH|W<`|;xLq++kv5k8VWZgQe*`_u+opEF8>A6qjM%k#skzbiuJ7dL_*><K@9l6!M*H(|w)PZJ2`RYy7K2VVrv+zc)&2Fc?wvh|^#ksyymE?D!Q$3!LbFX%h%vT%1#lr486Iybw?0!`H)ZlZ#XIao2uXTr}(IBl@wRWHa#})bgV);O3HoW7+T*!5M3=^mu6Ri$`7L;uUWj~gsqR6gQR9h7^nKdBIgy>ats36%|M|8p1x;32(ZfK9R5_xK5ts=Sz70c%SIK&g3N1E|sg{n3>JSbKwwhssGcb$8uMNw=Nv;f_;rj?}kz(3-&#FQw@O;q(8nGHjbrTC(NQv=ckXT|eHr|amahCq(7T6<LBTr5Gj>fHV~3DcYINN!Qr`6Dl?jT>!4u5~bb%Zi6VTax;%vg*m325J_$nEC%yqbbYeEp!K_K7k)W-XCP`6+}N7tktMVX+{@c2L&kLAc&IvspGrzZ$F`uOBg}fA3W2neAU}tg~<+iCN=<sR^Zke+9WNhnCyy6!8nfa>33&OWiPt2s=OMTrUgilSYQxrG!gziB!Aj83zX&6S|yjIQkA?iF0n%?<+B=%_D11aoCv?@Q&eei{sqNkr7RG`#*xyzSUE6BUNnZK)3|3Wls}K$qaKv;jOO#!{3Ms)4CQ?shafnAF^zVq(`K9o2xL5JoQoGea+W1$+xmw&8OMOtN1Pid6UAcd+*_bB6IY$KjrO=ac^tPv3(8O`&(agOBbT{Va6s}Rm9&`I#yivC;MhW8=n+^^&Reho;~!~W<xgH6bVq3^=H7)sUXV2nv~DP4`CY`f55i&qH)DvPMQy>)y*Z=|68w@v=#oo5^RSh5R2F%1-vt>h=|+1n0pE^Yq-72!)1+o{hD_3<Cyxpyr6r%cei-AFQ*h1seM$MP>ovLS2k#Ci$to#do$s3MXu2lZsw~9HkbjVWM@1!{w>}LWVj#j2qC(+*Okc>=<qcV}*}+U_QK+(ZZ(x>ZMdDDWtgHiBK+7p6aHHI`u-h6z7|Xm`>D1t4uEp271y7oCI^{1^H~O7QRxTA_U&92Q8z$J2O|5Lbeg_0umd^pSU<%-ki7LtDvo&AgIt0h~6(y@Hr+kyLJ$<B#07KdGob0EW$7@f{GszaUv#tkpSyk759Khmvq-aiyM-_&x_VCTx$Vy<;$<k{T$-@{Mhc<<%KD1AHK^MKkg%pYIW}SxhV?&a{o9=rs@*+hqyoioE=TF>9S<KxY+^69^OA0jkS#0!w@kw4}KTcP9#+PVW+qB|7B`Y?eRs+7}8RSAs?i?-Cz#Wp(Iihd`nI!Q_i%R^o_;fvDQ5|{Cr;yWeirL>_l#(wn)$QenJkK6Sgw)5NleBzvo&G#@>X`7Ib*aS4LHx9epI%BXXV&y7LJ&54g}D25-Q8>DZQ5hGKyIeJkQQu08%j|<x~)q(AOVw9P~Z*c0Z@VM6n#<}tBT6+T%4mZ9f*y76xlEFM~o$xr9*SZHd^6D-C!pkkp3m(-~W3&>KY@106L+;I><MJ^Dz`f{(I3i?u`2pWjUjlwZx`B1JB#h#u3xTH*b1K?TG40|4lxF1$_Pw+t?h2')).decode()).group(1))
The idea is hash the image and find the corresponding string from a dictionary (just like other answers).
The key code is this:
adler32(open(sys.argv[1]).tobytes()[2::6])%2003
We open the file, and then convert it into a 1024-byte string of RGBA values. With a bit of experimentation, we find that the ADLER-32 checksum of every sixth byte of this byte string is unique for these 132 images. And then further testing shows that, taking modulus of 2003 of the checksum gives the smallest dictionary.
The original dictionary looks like:
{
3: 'Programming Puzzles & Code Golf',
6: 'Science Fiction & Fantasy',
7: 'Bitcoin',
8: 'Biblical Hermeneutics',
…,
1969: 'Unix & Linux',
1989: 'WordPress Development',
1993: 'Cognitive Sciences',
2001: 'Personal Productivity',
}
We noticed that all site names do not contain numbers. Therefore we could concatenate the whole dictionary into a single string:
"256Software Quality Assurance & Testing3Programming Puzzles & Code Golf1284Geographic Info…"
And then use the regex e.g. 1969(\D+) to extract the site name. This huge string is then compressed to save space (let the compression engine notice the multiple occurrences of "Language"), and finally base-85 encoded.
Since it is now also tagged as kolmogorov-complexity, here a 2394-byte solution that does not use compression (zlib is still imported for adler32).
import sys,re,zlib,PIL.Image as i
l=' Language'
s='Science'
print(re.search(str(zlib.adler32(i.open(sys.argv[1]).tobytes()[2::6])%2003)+'(\\D+)','256Software Quality Assurance & Testing3Programming Puzzles & Code Golf1284Geographic Information Systems517Windows Phone6'+s+' Fiction & Fantasy7Bitcoin8Biblical Hermeneutics1034Writers1803Ask Different781Joomla597Islam1809Craft CMS878English'+l+' & Usage431Freelancing1565Politics32LEGO Answers289Physical Fitness1316Spanish'+l+'1830Database Administrators296Pets1066Philosophy1582Ask Patents560Cryptography1073Magento1588MathOverflow1333Salesforce1591Linguistics1844Stack Apps948Japanese'+l+'572Electrical Engineering778Genealogy & Family History735Sound Design63Open Data505Tridion328Arqade1609Hinduism588Music, Practice & Theory1101Expatriates846Network Engineering79German'+l+'1104Webmasters1208Signal Processing118Puzzling867ExpressionEngine Answers654Buddhism1593Quantitative Finance1625Parenting859Biology1117Academia1118Stack Overflow353Project Management1123Motor Vehicle Maintenance & Repair612Chinese'+l+'876Startups877Video Production110Reverse Engineering701French'+l+'677Bicycles1683Ebooks1908Blender190Physics1654Beer119History of '+s+' and Math1913Android Enthusiasts634Chemistry1252Travel1148Cross Validated1662Italian'+l+'565Sustainable Living387Programmers797Arduino1932Data '+s+'141Server Fault1422Chess109Amateur Radio147Computational '+s+'917Home Improvement1599Worldbuilding1438Mi Yodeya197Christianity1185Community Building1956Aviation1701Poker1703Mathematics Educators1704SharePoint425Meta Stack Exchange171Code Review1964Game Development1967Homebrewing944User Experience1969Unix & Linux1715Board & Card Games1716Graphic Design969Tor696Economics955Drupal Answers1213Raspberry Pi958The Great Outdoors885Mathematics1731Emacs1989WordPress Development910Photography1736Space Exploration1993Cognitive '+s+'s1227Computer '+s+'1230Mathematica207Gardening & Landscaping2001Personal Productivity1235Super User1358Information Security727Theoretical Computer '+s+'1497Earth '+s+'220Russian'+l+'1914Role-playing Games1758Movies & TV479Anime & Manga67English'+l+' Learners228Web Applications485Robotics593The Workplace232Astronomy1519Personal Finance & Money808Stack Overflow in Japanese1266Seasoned Advice467Software Recommendations1012Sports332Stack Overflow in Portuguese761History763Ask Ubuntu1957Skeptics85TeX - LaTeX').group(1))
Node.js, 3178 3130 2667 2608 Bytes
Computes the SHA1 hash of each file's image data and using bytes 16 through 19 of the hex digest, indexes the site names.
Using bytes 12 through 16 of the hex digest of each file's SHA1 hash, indexes the site names. There may be a shorter combination using only 3 bytes of the hex digest.
function $(e){r=require;r("pngparse").parseFile(e,function(e,t){console.log("Academia;Android Enthusiasts;Anime & Manga;Ask Different;Arduino;Ask Ubuntu;Astronomy;Aviation;Video Production;Beer;Bicycles;Biology;Bitcoin;Blender;Board & Card Games;Stack Overflow in Portuguese;LEGO Answers;Buddhism;Chemistry;Chess;Chinese Language;Christianity;Programming Puzzles & Code Golf;Code Review;Cognitive Sciences;Community Building;Seasoned Advice;Craft CMS;Cryptography;Computer Science;Theoretical Computer Science;Data Science;Database Administrators;Home Improvement;Drupal Answers;Signal Processing;Earth Science;Ebooks;Economics;Electrical Engineering;English Language Learners;Emacs;English Language & Usage;Expatriates;ExpressionEngine Answers;Physical Fitness;Freelancing;French Language;Game Development;Arqade;Gardening & Landscaping;Genealogy & Family History;German Language;Geographic Information Systems;Graphic Design;Amateur Radio;Biblical Hermeneutics;Hinduism;History;Homebrewing;History of Science and Math;Islam;Italian Language;Stack Overflow in Japanese;Japanese Language;Joomla;Mi Yodeya;Linguistics;Magento;Martial Arts;Mathematics;Mathematics Educators;Mathematica;MathOverflow;Motor Vehicle Maintenance & Repair;Meta Stack Exchange;Personal Finance & Money;Movies & TV;Music, Practice & Theory;Network Engineering;Open Data;The Great Outdoors;Parenting;Ask Patents;Pets;Philosophy;Photography;Physics;Project Management;Poker;Politics;Personal Productivity;Programmers;Puzzling;Quantitative Finance;Raspberry Pi;Reverse Engineering;Robotics;Role-playing Games;Russian Language;Salesforce;Computational Science;Science Fiction & Fantasy;Information Security;Server Fault;SharePoint;Skeptics;Software Recommendations;Sound Design;Space Exploration;Spanish Language;Sports;Software Quality Assurance & Testing;Stack Apps;Stack Overflow;Startups;Cross Validated;Super User;Sustainable Living;TeX - LaTeX;Tor;Travel;Tridion;Unix & Linux;User Experience;Web Applications;Webmasters;Windows Phone;WordPress Development;The Workplace;Worldbuilding;Writers".split(";")[x=r("crypto").createHash("sha1").update(t.data).digest("hex").slice(16,20),x=="c7da"?27:"f38c4a899f50c7d09a0f9dde6e05bbaebb274fc59f1ba9c4b8c315490f3d887b55f27c526f6f79c7db63f12feccafebf80fde98b13f6f6dbb8e59d6b97a09fe8cb0101f6abc8c963004f2f1aafbe216457ef8210ea104d841381d529cdd2697cf809f3d5cb0f1d91d970a981c41fe617d62c01284afdbbf78588490de40a56a0c7e613480354d13a738a84fc0bf2433d2351d585039c9795f8167997d15c1b2c8144ca40223794e66864608e305d5271faddc88177ef9d44bbd4c752b9d938ec92af827550fb".match(/.{3}/g).indexOf(x.slice(0,3))])})}