JPEG Amathuluzi

Tshintsha JPEG kuya futhi kusuka kumafomethi ahlukahlukene

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Mayelana JPEG

I-JPEG isebenzisa ukucindezela okulahlekile okwenzelwe izithombe, ikhwalithi yokulinganisela kanye nosayizi wefayela.

Ukusetshenziswa Okuvamile

Izithombe zedijithali
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JPEG Ukushintsha

Yini ihele JPEG?

I-JPEG (Iqembu Elihlangene Labachwepheshe Bezithombe) iyindinganiso yokucindezelwa kwesithombe sezithombe zedijithali.

Ingabe ukulondoloza kabusha i JPEG kwenza kube nzima ngaso sonke isikhathi?

Yebo, futhi lokho kuyinto eyodwa efanele ukwazi mayelana nefomethi. Ukugcina ngalunye kuphinde kuqhube umbhalo odlulile kusithombe esivele sidlule kulo, ngakho-ke ama-artefacts axhunywe - abonakala njenge-blocking ngaphesheya kombhalo kanye nama-haloes ezimbozweni ezinzima ngemuva kwekhulu elincane leminyaka. Hlela kusuka ku-master engalahleki futhi ukhuphule ku JPEG kabili, ekugcineni, endaweni yokuvula futhi ugcine kabusha ifayela elifanayo. I-bitstream ifana ne-.jpg: DCT-based lossy compression, ngokuvamile nge-4:2:0 chroma subsampling, ifakwe ku-JFIF noma Exif header.

Kungani zonke ikhamera nefoni ziminikeza JPEG?

Ngenxa yokuthi iyifomethi i-photographic chain yonke ihlala eminyakeni eminingi edlule, futhi akukho okuzosiza ukuvimbela ukuhambisana kwe-camera maker. I-data yesenzo iphathwa futhi ikhodwe kwi-camera, ku-quality setting ehlotshiswe kwimenyu, futhi okusetshenziswe kwikhadi liyisithombe esiqediwe. Lokhu kusho ukuthi ukuguqulwa lokuqala lwesithombe akuyona inqubekela phambili elahlekile abantu abakhathazekile ngayo — inqubekela phambili elahlekile idlule, ngaphakathi kwe-camera. I-JPEG iyisimo esifanayo njenge-JPG ne-JFIF — isibonisi esiyisithupha siyisisekelo, futhi isibonisi esiyisithathu sikhona kuphela ngenxa ye-DOS 8.3 isinqumo segama lefayela.

Ingabe JPEG ifana nefomethi njengenye ingqikithi yayo?

Yebo. Lezi zibanzi kanye negama elide noma elincane okubona ngakwesokudla lichaza uhlobo oluthile olungaphansi, futhi noma yini efunda noma ifunda zombili. Izibizo ezimbili ziyimlando: i-8-character filename limit from the DOS era, a vendor naming of its application rather than its file format, or two programs that simply defaulted differently. Converting either produces the same result, so use whatever extension the software at the other end is expecting.

Yini isilungiselelo sekhwalithi okufanele ngiyisebenzise uma ngiguqula ku JPEG?

Ngaphakathi kuka-80 no-90 nganoma yini umuntu uzoyibheka. Ngaphansi kuka-75 i-artefacts iqala ukubonisa kusikhumba, izulu kanye nanoma iyiphi indawo enkulu ehlanzekile; ngaphesheya kuka-95 ihele likhula ngokushesha ngenkathi akukho muntu okwaziyo ukubona ushintsho. Isilungiselelo asiyimpahla yesithombe, kuyisinqumo mayelana nale mpahla engaphandle ekhethekile — ngakho khetha lapho ihele lizohamba khona, futhi gcina okuyinhloko ngesikhathi esilandelayo lapho ufuna impendulo ehlukile.

Kungani isizinda sami esicacile sishintsha sibe mhlophe ku JPEG?

Ngenxa yokuthi JPEG ayinaso isixhumi se-alpha sokugcina. I-pixel ngayinye kufanele ibe nombala oqinile, ngakho ukubukhali kuhlanganisene nendawo yangaphambili - okumhlophe ngokuzenzakalela - ngesikhathi ihele libhalwe. Akukho okuzobuyiselwa emuva. Uma isithombe sidinga ukuhlala kwikhasi elimnyama noma ngaphezulu kwesithombe, guqula kufomethi egcina ukubukhali endaweni. I-JPEG ihlanganisa wonke ama-JPG alinganiselwe — akukho i-alpha, ukulahleka kosuku lokuzalwa ku-re-save — nge-noise engeziwe yesoftware ephatha izixhumanisi ezimbili ngokuhlukile.

Ingabe JPEG igcina umbala we-CMYK wokuphrinta?

Kungenza, ngakho amafayela ephrinta asuka emithonjeni yomsebenzi avame ukubukeka ahlukile kusikrini: amamibala acaciswa ngezinga le-ink elisengxenyeni ye-press kune-light ye-monitor. Amafomethi amaningi we-web-facing yi-RGB kuphela, ngakho ukuguqulwa kufanele kuguqulwe, futhi ukuguqulwa kulinganiselwa — u-cyan ogcwele no-orange ushintsho kakhulu. Kunoma yini ehamba kuphrinta, gcina okususelwa kunoma yini oguqula.

Ingabe kubaluleke ukuthi JPEG ingaphezu kweminyaka engu-30?

Ubudala bukhona akuyona inkinga - amafomethi amaningi onyaka akhona alungile, ngokucacile ngoba konke kudlule iminyaka eminingi ukuwafaka. Okubalulekile ukuthi unyaka uthathe isinqumo: amafayela amancane, amaprosesa aphansi, akukho nethiwekhi, futhi amakhono angeke afune umuntu. lapho amanani ahlala khona, ifomu lilungile. lapho ayikho, lena yisizathu sokushintsha.

Ingabe ikhamera nendawo yedatha yemeta igcinwa uma ngiguqula i JPEG?

Ithwala lapho ifomethi efuna ukufinyelela isekela khona - imodeli yekhamera, ukuboniswa, isikhathi sokuqoqa, kanye ne-GPS coordinates uma isisetshenziswa sizorekhoda. Le yamuva ifanele ukucabanga ngaphambi kokuthunyelwe: isithombe esihamba phambili esisuka kufoni singathwala indawo efanele ethathwe. Nciphisa i-metadata ngesikhathi sokushintshana uma isithombe sihamba endaweni esemthethweni.

Ingabe ngisebenzisa JPEG ngokuqondile kwikhasi le-web?

Yebo — wonke umsakazi okhona uyenza ngokusemthethweni, ngakho-ke adinga ikhophi engekho futhi adinga ukuguquka ngesikhathi sokushicilela. Imibuzo ekhona isisindo ngaphezu kokuxhasa: isithombe esifanayo kwifomethi yewebhu yamanje sivame ukuba isithathu sobukhulu ngekhwalithi ebonakalayo efanayo, okudinga ukukwenziwa nganoma yini ebonakala phezulu kwe-fold. I-JPEG iyisibonisi esibanzi esithandwa kakhulu yikhamera, isibhamu kanye nesofthiwe esuka ku-Unix, futhi itholakala emhlabeni wonke.

Ingabe ngingenza ngiphinde ngibize isiqephu endaweni yokushintsha JPEG?

Kunzima kakhulu, futhi kufanelekile ukuqonda ukuthi kungani: isithonjana siyisihloko, ngenkathi ama-bytes ngaphakathi kufakwe ngefomethi eyodwa ekhethekile. Ukushintsha igama kwenza ihele igama lakhe lithembisa okuthile okuqukethwe kwayo akusho ukunikela, futhi noma yini evula ihele noma liyiphoqa noma liyifunda kabi. Ukuphela kwephutha elincane yifomethi ezimbili ezikhona ngokusemthethweni ibhokisi elifanayo ngaphansi kwezinhlamvu ezahlukene — futhi ngisho lapho ukuphinda ubhale kahle kuphephile kunalokho ukushintsha igama.

Ingabe ngiguqula isibaya esigcwele se JPEG amafayela ngasikhathi sinye?

Nge-akhawunti, yebo — khiphana ndawonye futhi zibekwe njengemisebenzi eyodwa endaweni yokuphathwa ngayinye ngasikhathi sinye, ngezinhlelo ezifanayo ezisetshenziswa ngaphesheya kweqembu futhi izimpendulo zibuyiselwe ndawonye. Ukuguquka okumahhala kusebenza ihele elilodwa ngasikhathi sinye (amathuluzi okuxhuma athatha amabini); i-plan ekhokhelwa yilokho okuvulela ukuqhubekeka kweqembu kanye nobukhulu bomgwaqo wefayela ngalinye, okukwenza ukuguquka kwehele lonke lisebenze.