i'm currently in the process of conceptualizing an art piece for a gallery show next year, so this bizarre question of mine is more than just simple curiosity.

if i open up an image file (a .PNG) with Text Edit or Note Pad, the file is presented in textual characters. something like this except:

æº"í=™?0Ù:Ã,ÏI8^?K¯pmDHƒÃ?;wÔlD DDF›ä™èÜE[E˜ƒê?¯ƒºäeèçã?'ów+æ1ï‡ê0òHõñ?ò$úîù¥{WÎn}2*Ÿ!y(Ö!%2e9U2µ i4Õ(?=ù(›7}:É?##„G¶VfcVñ[÷D6gvrˆvéZN›=Ù=ó{púp…p?Ók‹oÃvŒÛ»{ùœóüôøW†W–VH\P?P$VTPt^lQ‹_B_S=Q™\Z[Ü)s/{]Œ_û]~¯¿¯Awu˜ùä’JÖ Í*tï[’ÎáÔ=<Æ6?~ZCWSÛpVµ?±ØŒ?nÆ^¨æ??™¡?a¥ë£1µÒÁ#?Gè)G<^mRl™m?jˆj~€"“R–Úª’?u?çO-•m˜â?ìéväˆàˆOä5ùXùûù”]¬]?]›V›œ{X{Óˆ|Ô’Èm{J?4‰Èáæõ}??~Á?óºYáœåüuRFÆ>W|^3Ñ5‰94=,<ú?|1b=2< >ö:?sÃ`¨{úf<f|ÛÖ?ãÊ    íâ–âè/_÷O¬}Â?Í›§Ãd’kÃkØ?sSíS? ??øy;-6]ˆ?÷ÌÌÙåËLÈ,l÷uvzNtÆt6Ô6?O ?P?_t_|°N¸]Ÿ{ƒ{è˜3KK> ?x~ò[ñ\ÆXA?x?Ãî?X?    ?…°”¸™‘jÂzÕkm~]jObµ·p1°Y‚s?&b”}s?ãËóí-»ñ”÷‰?‡v?ˆ˜WõØ£??æe~;¸n?Ooáa'aÁÎÌ-ª$ª!ª~ ?¨‹CÏpÏO/Á›œ/?80<Ë<§8

can anyone explain what is happening here? are the characters some form translation of pixel data by the text editor? maybe it is completely meaningless / an error? if not, is there a name for this type of data conversion or process?