Ukucindezelwa Okulahlekile: Kuyini Futhi Kusetshenziswa Kanjani

ngo kim Kubuyekezwe: June 28, 2022

Ukucindezelwa okulahlekile indlela esetshenziswa ukunciphisa osayizi bamafayela edatha ngaphandle kokwehliswa ubuqotho bedatha yoqobo.

Ikwenza ukwazi ukuthatha amafayela amakhulu aqukethe idatha eningi futhi wehlise usayizi wawo ngawo ikhipha enye idatha kodwa ayithinti ikhwalithi iyonke. Lokhu kungaba yinzuzo ikakhulukazi lapho usebenza namavidiyo amakhulu noma amafayela ezithombe.

Okusele kwalesi sihloko kuzochaza izimiso zokucindezelwa kokulahlekelwa kanye ungasifaka kanjani isicelo futhi usisebenzise ngempumelelo:

Incazelo ye-Lossy Compression

Ukucindezelwa okulahlekile iwuhlobo lwesu lokucindezela idatha olusebenzisa izindlela zokunciphisa usayizi wefayela noma ukusakaza kwedatha ngaphandle kokulahlekelwa amanani abalulekile wokuqukethwe kolwazi. Lolu hlobo lokuminyanisa lukhiqiza amafayela amancane kunezinguqulo zawo zangempela kuyilapho liqinisekisa ukuthi ikhwalithi, ukucaca, nobuqotho bedatha kugcinwa. Isebenza ngokususa ngokukhetha izingxenye zedatha yemidiya (enjengomsindo noma izithombe) ezihlala zingabonakali ezinzwa zomuntu. Ukucindezelwa okulahlekile sekuneminyaka eminingi kukhona futhi ukusetshenziswa kwayo sekudume kakhulu ngenxa yentuthuko kwezobuchwepheshe.

Lolu hlobo lokucindezelwa lunenzuzo ezimeni lapho umkhawulokudonsa noma indawo yokugcina inomkhawulo, okwenza kube usizo ikakhulukazi ku:

• Ukusakaza-bukhoma izinhlelo zokusebenza ezifana ividiyo-on-demand (VoD),
• Ukusakaza ngesathelayithi,
• Isithombe sezokwelapha,
• Amafomethi omsindo wedijithali.

Le nqubo iphinde isetshenziswe kakhulu phakathi kwezinhlelo zokusebenza zomsindo nesithombe ukuze kugcinwe ikhwalithi ngamasayizi aphansi wefayela lapho ulondoloza ifayela lephrojekthi elihleliwe. Ukucindezelwa okulahlekile kungasetshenziswa kwezinye izinhlobo zedatha njengamafayela ombhalo inqobo nje uma kungekho okuqukethwe kwangempela okubalulekile okulahlekile phakathi nenqubo.

Ngokuphikisana ukulahlekelwa ukuqonda, nakhu ukucindezela okungenakulahlekelwa ezama ukunciphisa ukuhlanekezela phakathi kokusakazwa kwedatha okokufaka nokuphumayo ngaphandle kokunciphisa ukucaca kombono ngokusebenzisa ulwazi olungadingekile olusuka ngaphakathi komthombo ngokwawo esikhundleni sokususa noma yiluphi ulwazi kuwo.

Izinzuzo Zokucindezelwa Okulahlekile

Ukucindezelwa okulahlekile iyindlela ephumelelayo yokunciphisa usayizi wefayela kuyilapho ulondoloza ikhwalithi yesithombe iyonke. Ngokungafani nendabuko eyengeziwe amasu okucindezela idatha angalahleki, ezikhetha futhi zilahle ukuncipha kwedatha ukuze kuncishiswe usayizi nokwandisa isivinini sokudlulisela, ukucindezela kokulahlekelwa kusebenza ngokukhetha ukulahla ulwazi olungabalulekile nolungenamsebenzi efayeleni. Lolu hlobo lokucindezelwa lusebenzisa ama-algorithms ukuhlaziya idatha ngaphakathi kwefayela ledijithali futhi kususe izingxenye ezingadingekile ngaphandle kokuthinta kakhulu ikhwalithi iyonke noma umphumela wokuphela.

Uma isetshenziswe kahle, ukucindezela kokulahlekelwa kunganikeza izinzuzo eziningi, njenge:

• Izimfuneko zesitoreji ezehlisiwe: Ngokususa imininingwane engabalulekile kufayela ledijithali, usayizi wesithombe owumphumela ungaba mncane kakhulu kunozakwabo wangempela, unikeze ukonga okukhulu kwesitoreji kubaphathi bewebhu.
• Izivinini zokudlulisa ezithuthukisiwe: Ama-algorithms wokucindezela okulahlekelwa asebenzisa idatha encane ngokususa ulwazi olungadingekile esithombeni esingabonakali ngeso lomuntu. Lokhu kusho ukuthi amafayela asakazwa kuwo wonke amanethiwekhi angashesha kakhulu kunezinguqulo zawo zangempela ngaphandle kokudela ikhwalithi.
• Umuzwa wokubuka othuthukisiwe: Ngokuncipha okukhulu kosayizi wefayela kuza ukuzizwisa okuthuthukisiwe kokubuka ngenkathi upheqa ku-inthanethi noma ubuka izithombe kumadivayisi eselula. Izithombe ezicindezelwe ezilahlekile zithatha inkumbulo encane kuma-hard drive edivayisi esiza ngokusebenza kokunikezelwa kwesithombe lapho kulayishwa izithombe noma kuphequlula amakhasi ewebhu.

Izinhlobo Zokucindezelwa Okulahlekile

Ukucindezelwa okulahlekile kuyindlela yokucindezela idatha eyehlisa usayizi wefayela ngokulahla izingxenye zedatha yalo ezithathwa njengezingadingekile. Kuyasiza uku thuthukisa usayizi wefayela futhi ingasiza ekongeni indawo yokugcina. Lolu hlobo lwesu lokucindezela lungasetshenziswa ezinhlelweni ezahlukahlukene ezifana nesithombe, umsindo, namafayela wevidiyo.

Kulesi sihloko, sizoxoxa nge izinhlobo ezine zokucindezelwa kokulahlekelwa, izinzuzo zabo, kanye nebubi:

I-JPEG

I-JPEG (Iqembu Elihlangene Lochwepheshe Bezithombe) iyindinganiso ye ukucindezelwa okulahlekile kwezithombe zedijithali. I-JPEG isekela izithombe ezingu-8-bit, ezimpunga nemifanekiso yemibala engamabhithi angu-24. I-JPG isebenza kahle kakhulu ezithombeni, ikakhulukazi lezo ezinemininingwane eminingi.

Uma kwakhiwa i-JPG, isithombe sihlukaniswa sibe amabhulokhi amancane abizwa ngokuthi 'ama-macroblocks'. Ifomula yezibalo yehlisa inani lemibala etholakalayo noma amathoni kubhulokhi ngayinye futhi isusa ukungapheleli okubonakala kithi, kodwa hhayi kumakhompyutha. Irekhoda zonke izinguquko ezenziwe kulawa mabhulokhi ukuze ibuyele phezu kwawo futhi irekhode izimo zawo zangempela ukuze kuncishiswe usayizi wawo. Uma isithombe silondolozwe njenge-JPG, sizovela sihluke kancane kuye ngokuthi kungakanani ukuminyanisa okusetshenzisiwe ukuze kuncishiswe usayizi waso. Ikhwalithi yesithombe iyehla uma amanani aphezulu okucindezela asetshenziswa futhi ama-artifact angase aqale ukuvela – kanye nomsindo namaphikiseli. Lapho ulondoloza isithombe njenge-JPG ungakhetha ukuthi kungakanani ukucaca okudingeka kunikelwe ukuze kuncishiswe izinga losayizi wefayela - ngokuvamile okubizwa ngokuthi “izinga“. Lesi silungiselelo sithinta inani le ukucindezela okulahlekile esetshenziswa kufayela lakho.

I-MPEG

I-MPEG (Iqembu Lochwepheshe Bezithombe Ezinyakazayo) uhlobo lohlobo ukucindezela okulahlekile esetshenziselwa ngokuyinhloko amafayela alalelwayo namavidiyo. Yakhelwe njengendinganiso yokucindezela amafayela e-multimedia futhi isiye yaduma kakhulu ngokuhamba kweminyaka. Umqondo oyinhloko ngemuva kokucindezelwa kwe-MPEG ukunciphisa usayizi wefayela ngaphandle kokuphazamisa ikhwalithi - lokhu kwenziwa ngokulahla izici ezithile zefayela ezingabalulekile ngokubonwa yisibukeli.

Ukucindezelwa kwe-MPEG kusebenza ngokuhlaziya ividiyo, ukuyihlukanisa ibe izingcezu, nokwenza izinqumo mayelana nokuthi yiziphi izingxenye ezingalahlwa ngokuphephile, kuyilapho kugcinwa izinga elamukelekayo lekhwalithi. I-MPEG igxile ku izingxenye ezinyakazayo kufayela levidiyo; izinto ezinganyakazi esigcawini kulula kakhulu ukuziminyanisa kunezinto ezihambayo noma ezinoshintsho olusheshayo embaleni noma ekukhanyeni kokukhanya. Isebenzisa ama-algorithms athuthukisiwe, i-MPEG ingakha izinguqulo eziphumelelayo zozimele ngamunye ngaphakathi kwefayela bese isebenzisa lawo mafreyimu ukumela izingxenye ezinkulu zesigcawu.

Inani lekhwalithi elilahlekile ngenxa yokucindezelwa kwe-MPEG lincike kukho kokubili i-algorithm ekhethiwe kanye nezilungiselelo ezisetshenzisiwe. Ukuhwebelana lapha kuphakathi kosayizi nekhwalithi; izilungiselelo eziphakeme zizoveza imiphumela engcono kodwa ngezindleko ezinkulu ngokwesikhala; ngokuphambene, izilungiselelo eziphansi zizokhiqiza amafayela amancane anokulahlekelwa kwekhwalithi okuphawulekayo, ikakhulukazi uma kuziwa amavidiyo amakhulu njengamafilimu anobude besici noma amavidiyo anokulungiswa okuphezulu afanele ama-HDTV.

MP3

MP3, noma Izithombe Ezinyakazayo Isazi Iqembu Lomsindo Layer 3, ifomethi yomsindo ecindezelwe esebenzisa uhla lwama-algorithms athile ukunciphisa usayizi wangempela wamafayela alalelwayo. Ibhekwa njengenye yezakhiwo ezidume kakhulu ngenxa yokusebenza kahle kwayo ekucindezeleni izingoma zomsindo wedijithali zibe osayizi abancane kunabanye okulahlekayo amafomethi. I-MP3 isebenzisa indlela “elahlekile” yokuminyanisa esusa enye idatha yokurekhodwa kwasekuqaleni futhi yenze kube lula kumadivayisi afana nezidlali zomculo eziphathwayo ukuthi zigcine futhi zisakaze inani elikhulu lomculo wedijithali.

I-MP3 ingacindezela noma yiluphi uhlobo lwemiksi yedijithali kusukela i-mono, i-mono eyimpinda, isitiriyo, ishaneli ekabili nesitiriyo esihlanganyelwe. Izinga le-MP3 lisekela i-bit-rate engu-8-320Kbps (amakhilobhithi ngomzuzwana) iminyanisa idatha yezwi ibe ngu-8kbps elungele izinjongo zokusakaza-bukhoma. Inikeza amazinga aqhubekayo aphezulu ekhwalithi yomsindo efika ku-320Kbps ngokuthembeka okuphezulu komsindo kanye ne-bitrate ephakeme enikeza ikhwalithi yomsindo enjengempilo eyengeziwe ngosayizi wefayela okhulisiwe okuholela ezikhathini zokulanda ezihamba kancane. Uma usebenzisa le ndlela yokuminyanisa, kungaba okujwayelekile kubasebenzisi ukuzuza isilinganiso 75% ukuncishiswa kosayizi wefayela ngaphandle kokulahlekelwa ekujabuleleni ukulalela noma ukucaca ngenxa yesistimu yayo yokubhala amakhodi edlulisela kahle amanani amakhulu edatha kuyilapho igcina ikhwalithi yomsindo efanele.

Indlela Yokusebenzisa Ukucindezelwa Okulahlekile

Ukucindezelwa okulahlekile wuhlobo lokucindezelwa kwedatha okunciphisa ifayela ngokuthi ikhipha enye idatha yayo. Lokhu kuzoholela kusayizi wefayela omncane futhi ngenxa yalokho, isivinini sokulanda ngokushesha. Ukucindezela okulahlekile kuyithuluzi elihle ongalisebenzisa uma udinga ukucindezela ngokushesha amafayela amakhulu.

Kulesi sihloko, sizoxoxa:

• Isetshenziswa kanjani ukucindezela okulahlekile
• Yiziphi izinzuzo
• Indlela thuthukisa amafayela owacindezelayo

Umhlahlandlela Wezinyathelo Ngezinyathelo

Ukusebenzisa ukucindezela kokulahlekelwa ngokuvamile kudinga izinyathelo ezilandelayo:

1. Khetha uhlobo lwefayela noma idatha ofisa ukuyiminyanisa - Ngokuya ngosayizi wefayela oyifunayo kanye nezinga lekhwalithi, uhlobo lwefomethi ecindezelweyo lungahluka. Amafomethi ajwayelekile ahlanganisa JPEG, MPEG, futhi MP3.
2. Khetha ithuluzi lokucindezela - Amathuluzi okucindezela ahlukene asebenzisa ama-algorithms ahlukene ukuze enze amazinga ahlukahlukene wokucindezela ifayela. Amanye amathuluzi adumile WinZip, zipX, 7-Zip futhi WinRAR kubasebenzisi beWindows; Izinto X kubasebenzisi be-Mac; futhi iZarc kubasebenzisi bezinkundla eziningi.
3. Lungisa izilungiselelo zokuminyanisa - Ukwakha umphumela ofanelane kakhulu, yenza izinguquko ezinjengokushintsha izinga lokuminyanisa, ukulungiswa kwesithombe noma ezinye izilungiselelo ezishumekiwe ngaphakathi kwefomethi ecindezelwe ngaphambi kokuminyanisa idatha. Futhi bheka izilungiselelo ezithuthukisa izithombe ukuze zibukwe kuwebhu uma zikhona.
4. Cindezela ifayela noma idatha - Qala inqubo yokuminyanisa ngokuchofoza ukuqala noma "KULUNGILE" kuhlelo lwakho lokusebenza uma usuqedile ukulungisa izilungiselelo zakho. Kuya ngosayizi wamafayela acindezelwayo, kungathatha amaminithi ambalwa ukuqedela le nqubo kuye ngesivinini sephrosesa nohlelo lokusebenza lwesofthiwe olusetshenzisiwe.
5. Ungacindezeli ifayela noma idatha - Inqubo yokukhipha izokuvumela ukuthi ufinyelele kumafayela akho asanda kushwabana uma eseqediwe ukuze uqalise ukuwasebenzisa ngokushesha kodwa eyifanele kakhulu iphrojekthi yakho eseduze. Finyelela amafayela owafunayo kumafolda acindezelwe izinhlobo ngokuvamile ziyahluka .zip .rar .7z .tar .iso njll.. Isizinda se-Unzip simane sikhiphe izingxenye ezithile ezicindezelwe ngezinhlelo zokusebenza ezifana WinZip, 7Zip, IZarc njl.

Ukwenza Okungcono

Lapho usebenzisa ukucindezela okulahlekile, kubalulekile ukusebenzisa ifomethi elungile kuhlelo lokusebenza olulungile. Isibonelo, uma udinga ukwabelana ngefayela lesethulo nabanye abantu, kufanele usebenzise a Ifomethi yesithombe esilahlekile njengoba izethulo zivame ukuboniswa ngokulungiswa okuphansi kanye nosayizi omncane.

Kunezindlela eziningana zokwandisa ukusebenza kahle kokucindezelwa kokulahlekelwa. Nansi eminye yemikhuba ehamba phambili:

• Khetha ifomethi yokucindezela efanelekile ngokuya ngodaba lwakho lokusebenzisa (i-jpeg yezithombe, i-mp3 yokulalelwayo, Njll).
• Setha ileveli yekhwalithi efanelekile kuye ngokuthi ingakanani idatha ofuna ukuyilahla.
• Lungisa amapharamitha ngokwezidingo zakho; hlaziya ukuhwebelana phakathi kosayizi wefayela nekhwalithi.
• Qaphela ukuthi ukufaka ukucindezela kokulahlekelwa kaningi ingangenisa izinto zobuciko ezibonakalayo kumafayela akho emidiya futhi yehlisa izinga labo okubaluleke kakhulu kunokudlula okukodwa kokucindezelwa kuvame ukwenza.
• Qiniseka ukuthi imethadatha ehlotshaniswa namafayela acindezelwe igcinwa ngendlela efanele ukuze lonke ulwazi olubalulekile luhlale lutholakala lapho kusakazwa noma kuboniswa izici zokuqukethwe kwefayela.

Isiphetho

Ekuphetheni, ukucindezela okulahlekile kuyindlela enhle yokunciphisa osayizi bamafayela nokunciphisa isikhathi sokulayisha kumawebhusayithi ngenkathi usagcina i-a izinga eliphezulu lekhwalithi. Ikuvumela ukuthi unciphise usayizi wefayela wesithombe noma ifayela lomsindo ngaphandle kokuba nomthelela omkhulu kukhwalithi yefayela. Kubalulekile ukukhumbula, nokho, lokho ukucindezela okulahlekile isazothinta ikhwalithi yefayela futhi kufanele isetshenziswe ngokucophelela.

Isifinyezo se-Lossy Compression

Ukucindezelwa okulahlekile wuhlobo lokucindezelwa kwedatha okunciphisa usayizi wefayela ngokususa olunye ulwazi oluqukethwe kufayela lokuqala. Le nqubo ngokuvamile iholela kumafayela amancane kunamafayela asekuqaleni futhi acindezelwe kusetshenziswa ama-algorithms afana nala I-JPEG, MP3 ne-H.264 ukubala abambalwa. Izindlela zokucindezelwa ezilahlekile zivame ukuhwebelana ngekhwalithi ethile ngosayizi kodwa ama-algorithms athuthukisiwe angakhiqiza amafayela anomehluko omncane kakhulu obonakalayo kokwangempela okungacindezelwanga.

Uma usebenzisa ukucindezela okulahlekile, kubalulekile ukucabangela ukuthi ingakanani ikhwalithi ezomukeleka kumgomo othile wokunciphisa usayizi wefayela. Okunye ukucindezelwa okulahlekile kunganciphisa osayizi bamafayela ngokumangalisayo kuyilapho kunikeza ukulahlekelwa kwekhwalithi encane uma kuqhathaniswa kuyilapho abanye bengase bakhiqize amafayela amancane kakhulu kodwa ngokuhlanekezelwa okungamukeleki noma ama-artifact. Ngokuvamile, uma kufunwa ukuncishiswa kosayizi okukhulu, khona-ke ukulahlekelwa kwekhwalithi enkulu kungalindelwa futhi ngokuphambene nalokho.

Sekukonke, ukucindezela kokulahlekelwa kunikeza indlela ephumelelayo yokunciphisa osayizi bamafayela ngaphandle kokudela ukusebenza okuningi uma kuqhathaniswa namafomethi angacindezelwanga ezimweni eziningi; nokho, lezi zinkinga kufanele zihlolwe ngakunye ngaphambi kokwenza isinqumo sokuthi ngabe iyisixazululo esifanelekile yini sesethi yenkinga ethile.

Izinzuzo Zokusebenzisa Ukucindezelwa Okulahlekile

Ukucindezela okulahlekile kunikeza izinzuzo eziningi kumafayela emidiya yedijithali. Inzuzo esobala kakhulu ukuthi ukucindezela kokulahlekelwa kunikeza izinga elikhulu ukuncishiswa kosayizi wefayela kunokwesiko ama-algorithms wokucindezela angalahleki. Lokhu kusiza ukugcina izimfuneko zokugcinwa kanye nokusetshenziswa komkhawulokudonsa zisezingeni eliphansi lapho udlulisela amafayela emidiya amakhulu nge-inthanethi, noma ngokuwacindezela ukuze agcinwe endaweni.

Ngaphezu kokunikeza ukuncishiswa okungcono kwesayizi wefayela kunezindlela zendabuko ezingalahleki, ukusetshenziswa kokucindezelwa kokulahlekelwa nakho kwenza kube nokwenzeka ukunciphisa osayizi bamafayela ngisho nangaphezulu ngenkathi kugcinwa izinga elamukelekayo lekhwalithi (kuye ngokuthi uhlobo lwemidiya ecindezelwayo). Ukwengeza, ukusebenzisa ama-algorithms alahlekile kuvumela abasebenzisi ukuthi lungisa endaweni yesithombe nekhwalithi yomsindo njengoba kudingekile ngaphandle kokufaka ikhodi kabusha lonke ifayela - lokhu kwenza ukulondoloza amafayela ephrojekthi kube lula futhi kusheshe kakhulu njengoba izingxenye zefayela lemidiya kuphela ezidinga ukushintshwa.

Okokugcina, ukusebenzisa ama-algorithms alahlekile kunganikeza nokuvikeleka okwengeziwe kwezinye izimo; njengoba umsindo ophansi we-bitrate ngokuvamile awuhlukani kakhulu futhi kunzima kakhulu ukuwuhumusha ngokufana uma uqhathaniswa nezinguqulo eziphezulu ze-bitrate, unganikeza isendlalelo esengeziwe sokuphepha uma amasethi edatha amakhulu edinga ukuvikelwa ekulaleleni okungagunyaziwe noma ekubukweni. Uhlu olubanzi lwezinzuzo zokucindezelwa kokulahlekelwa yenze idume phakathi kwabasebenzisi bemidiya yedijithali abafuna amafayela amancane ngomzamo omncane.

Sawubona, nginguKim, umama kanye nomshisekeli we-stop-motion onesizinda ekudalweni kwemidiya nokuthuthukiswa kwewebhu. Nginothando olukhulu lokudweba nokugqwayiza, futhi manje sengingena ngekhanda emhlabeni onyakazayo. Ngebhulogi yami, ngabelana ngezifundo zami nani bafana.