Kurasika Compression: Chii uye Mashandisiro Acho

by kim Updated: June 28, 2022

Kurasikirwa kwekumanikidza inzira inoshandiswa kuderedza saizi yefaira re data pasina kukanganisa kutendeseka kweiyo data yekutanga.

Inokuita kuti utore mafaira makuru ane data rakawanda uye kuderedza saizi yawo kubvisa imwe data asi kwete kukanganisa hunhu hwese. Izvi zvinogona kunyanya kubatsira kana uchibata nemavhidhiyo makuru kana mafaira emifananidzo.

Iyo yasara yechinyorwa ichi ichatsanangura misimboti yekurasikirwa nekumanikidza uye nzira yekuishandisa nekuishandisa zvinobudirira:

Tsanangudzo yeLossy Compression

Kurasikirwa kwekumanikidza imhando yedhisiki yekumanikidza data inoshandisa nzira dzekudzikisa saizi yefaira kana data stream pasina kurasikirwa nehuwandu hwakakosha hwehuwandu hwemashoko. Iyi mhando yekumanikidza inoburitsa mafaira madiki pane ayo ekutanga mavhezheni uku ichiona kuti mhando, kujeka, uye kutendeseka kwedata kunochengetedzwa. Inoshanda nekusarudza kudzima zvikamu zve data yenhau (senge odhiyo kana magirafu) izvo zvinoramba zvisingaonekwe nemanzwiro emunhu. Kurasikirwa kwekumanikidza kwave kuripo kwemakore mazhinji uye kushandiswa kwayo kwave kuwedzera mukurumbira nekuda kwekufambira mberi kwehunyanzvi.

Iyi mhando yekumanikidza inobatsira mumamiriro ezvinhu apo bandwidth kana nzvimbo yekuchengetera ishoma, zvichiita kuti inyanyo batsira mu:

• Kutepfenyura maapplication akadai vhidhiyo-pane-inodiwa (VoD),
• satellite kutepfenyura,
• Medical imaging,
• Digital audio formats.

Iyi tekinoroji inoshandiswa zvakare zvakanyanya mukati mekuteerera uye mufananidzo edhita maapplication kuchengetedza mhando neakaderera faira saizi paunenge uchichengeta yakagadziridzwa purojekiti faira. Kurasika kwekumanikidza kunogona kuiswa kune mamwe marudzi e data senge mameseji mafaera chero pasina akakosha ekutanga emukati akarasika panguva yekuita.

Kupesana na kurasikirwa nekunzwisisa, pane kudzvinyirira kusingarasikirwe iyo inoedza kuderedza kukanganisa pakati pekupinza uye kubuda kwe data streams pasina kuderedza kujeka kwekunzwisisa kuburikidza nekushandisa ruzivo rusina basa kubva mukati mezvinyorwa zvayo pachayo pane kudzima chero ruzivo kubva mairi.

Zvakanakira Lossy Compression

Kurasikirwa kwekumanikidza inzira inoshanda yekudzikisa saizi yefaira uchiri kuchengetedza huwandu hwemifananidzo. Kusiyana nemamwe echinyakare nzira dzisina kurasikirwa dzekumanikidza data, iyo inosarudza uye inorasa redundancies mu data kuderedza ukuru uye kuwedzera kukurumidza kutapurirana, kurasikirwa kwekumanikidza kunoshanda nekusarudza kurasa zvisina kukosha uye zvisina basa ruzivo mufaira. Iyi mhando yekumanikidza inoshandisa algorithms kuongorora iyo data mukati medhijitari faira uye kubvisa zvisingakoshi zvikamu pasina kukanganisa zvakanyanya kunaka kwese kana mhedzisiro.

Kana yakashandiswa nemazvo, kurasikirwa kwekumanikidza kunogona kupa akawanda mabhenefiti, akadai se:

• Zvido zvakaderedzwa zvekuchengetedza: Nekubvisa zvinyorwa zvisina basa kubva kudhijitari faira, mhedzisiro saizi yemufananidzo inogona kunge iri diki zvakanyanya pane yainotarisana nayo yepakutanga, ichipa yakakura kuchengetedza kuchengetedza kune webmasters.
• Kuvandudzwa kwekutapurirana kumhanya: Lossy compression algorithms inoshandisa shoma data nekubvisa ruzivo rusina basa kubva pamufananidzo usingaonekwe neziso remunhu. Izvi zvinoreva kuti mafaera anofambiswa pamanetiweki anogona kukurumidza kudarika mavhezheni awo ekutanga pasina kupira mhando.
• Yakavandudzwa yekuona chiitiko: Nekudzikisira kwakakosha kwesaizi yefaira kunouya yakavandudzwa yekuona zviitiko paunenge uchitsvaga pamhepo kana kuona mifananidzo panharembozha. Yarasika yakadzvanywa mifananidzo inotora ndangariro shoma pane dhiraivha yakaoma iyo inobatsira nemifananidzo inopa kuita kana uchirodha mafoto kana kubhurawuza mapeji.

Mhando dzeLossy Compression

Kurasikirwa kwekumanikidza idhizaini yekumanikidza data iyo inoderedza saizi yefaira nekurasa zvikamu zve data rayo zvinoonekwa sezvisina basa. Zvinobatsira gadzirisa saizi yefaira uye inogona kubatsira kuchengetedza nzvimbo yekuchengetera. Iri rudzi rwekumanikidza tekinoroji inogona kushandiswa mune akasiyana maapplication akadai semufananidzo, odhiyo, uye vhidhiyo mafaera.

Munyaya ino, tichakurukura mana marudzi ekurasikirwa kwekumanikidza, zvayakanakira nezvayakaipira:

JPEG

JPEG (Joint Photographic Experts Group) chiyero che kurasikirwa kwekumanikidza kwemifananidzo yedhijitari. JPEG inotsigira 8-bit, grayscale mifananidzo uye 24-bit mavara emifananidzo. JPG inoshanda zvakanyanya pamifananidzo, kunyanya idzo dzine ruzivo rwakawanda.

Kana JPG yagadzirwa, chifananidzo chinotsemurwa kuita mabhururu madiki anonzi '.macroblocks'. Formula yemasvomhu inoderedza huwandu hwemavara aripo kana toni mubhuroko rega rega uye inobvisa kusakwana kunotisvota, asi kwete kumakomputa. Inorekodha shanduko dzese dzakaitwa mumabhuroko aya saka painodzokera pamusoro padzo uye inorekodha nyika dzadzo dzekutanga kuti dzideredze saizi yavo. Kana foto yachengetwa seJPG, inoratidzika zvakasiyana zvichienderana nekuti yakawanda sei compression yakashandiswa kuderedza saizi yayo. Hunhu hwemufananidzo hunodzikira kana huwandu hwepamusoro hwekumanikidza hukaiswa uye zvigadzirwa zvinogona kutanga kuoneka - pamwe neruzha uye pixelation. Pakuchengetedza mufananidzo seJPG unogona kusarudza kuti kujekeswa kwakadii kunoda kubayirwa kuti ndeipi dhigirii rekudzikisa saizi yefaira - inowanzonzi "unhu“. Izvi zvinokanganisa huwandu hwe kurasikirwa kwekumanikidza inoshandiswa pafaira rako.

MPEG

MPEG (Moving Picture Experts Group) iri mufananidzo we kurasikirwa kwekumanikidza iyo inoshandiswa zvakanyanya kune odhiyo uye vhidhiyo mafaera. Yakagadzirwa seyero yekumanikidza multimedia mafaera uye yave kuwedzera mukurumbira nekufamba kwemakore. Pfungwa huru kuseri kweMPEG compression ndeyekudzikisa saizi yefaira pasina kukanganisa kunaka - izvi zvinoitwa nekurasa zvimwe zvinhu zvefaira zvisina kukosha kune muoni.

MPEG compression inoshanda nekuongorora vhidhiyo, kuitsemura kuita machunks, uye kuita sarudzo dzekuti ndedzipi zvikamu zvinogona kuraswa zvakachengeteka, uchiri kuchengetedza mwero unogamuchirika wemhando. MPEG inotarisa pa kufamba zvikamu muvhidhiyo faira; zvinhu zvisingafambi pachiitiko zviri nyore kudzvanya pane zvinhu zvinofamba famba kana kukurumidza kushanduka kweruvara kana kusimba kwechiedza. Uchishandisa advanced algorithms, MPEG inogona kugadzira vhezheni inoshanda yefuremu yega yega mukati mefaira uye yobva yashandisa iwo mafuremu kumiririra zvikamu zvakakura zvechiitiko.

Huwandu hwemhando yakarasika nekuda kwekumanikidza kweMPEG kunoenderana nezvose zvakasarudzwa algorithm uye zvigadziriso zvakashandiswa. The tradeoff pano iri pakati pehukuru uye kunaka; zvirongwa zvepamusoro zvichapa zvibereko zviri nani asi pamutengo mukuru maererano nenzvimbo; ukuwo, marongero epasi anoburitsa madiki mafaera ane zvakanyanya kuoneka kurasikirwa kwemhando, kunyanya kana zvasvika mavhidhiyo makuru akadai semafirimu-akareba-mafirimu kana mavhidhiyo ane-resolution akakodzera HDTVs.

MP3

MP3, kana Inofambisa Mifananidzo Nyanzvi Boka Audio Layer 3, idhidhiyo yakadzvanywa fomati iyo inoshandisa huwandu hwealgorithms kudzikisa saizi yekutanga yemaodhiyo mafaira. Iyo inoonekwa seimwe yeanonyanya kufarirwa mafomati nekuda kwekuita kwayo mukutsikirira nziyo dzedhijitari mumasikisi madiki pane mamwe kurasikirwa formats. MP3 inoshandisa “kurasika” nzira yekutsikirira iyo inobvisa imwe data yepakutanga yekurekodha uye inoita kuti zvive nyore kumidziyo yakaita sevanotamba mimhanzi inotakurika kuchengetedza uye kufambisa yakawanda yemimhanzi yedhijitari.

MP3 inogona kudzvanya chero mhando yemusanganiswa wedhijitari kubva mono, duplicate mono, stereo, dual channel uye joint stereo. Iyo MP3 yakajairwa inotsigira 8-320Kbps bit-rate (kilobits pasekondi) inodzvanya data yezwi mu8kbps iyo inokodzera kutenderera. Iyo inopa zvishoma nezvishoma mazinga emhando yekurira kusvika ku320Kbps ine ruzha rwepamusoro uye yakakwira bitrate ichipa inotowedzera hupenyu hwemhando yeruzha pane yakawedzera saizi yefaira zvichikonzera kunonoka kurodha nguva. Paunenge uchishandisa iyi compression nzira, zvingave zvakajairwa kuti vashandisi vawane avhareji 75% faira rekudzikisira saizi pasina kurasikirwa mukunakidzwa kwekuteerera kana kujekesa nekuda kweiyo coding system iyo inofambisa zvinobudirira huwandu hukuru hwe data ichichengetedza yakakodzera ruzha rwemhando.

Maitiro Ekushandisa Lossy Compression

Kurasikirwa kwekumanikidza imhando yekudzvanya data iyo inoderedza faira ne kubvisa imwe data yayo. Izvi zvinozokonzera diki faira saizi uye nekudaro, nekukurumidza kurodha kumhanya. Lossy compression chishandiso chikuru chekushandisa kana iwe uchida kukurumidza kumanikidza mafaera makuru.

Muchikamu chino, tichakurukura:

• Kushandisa sei kurasikirwa kwekumanikidza
• Ndezvipi zvinobatsira
• sei gadzirisa mafaira aunomanikidza

Nhanho-nhanho Nhungamiro

Kushandisa kurasikirwa kwekumanikidza kunoda matanho anotevera:

1. Sarudza rudzi rwefaira kana data raunoda kudzvanya - Zvichienderana neinoda mhedzisiro saizi yefaira uye nhanho yemhando, mhando yefomati yakamanikidzwa inogona kusiyana. Mafomu akajairika anosanganisira JPEG, MPEG, uye MP3.
2. Sarudza mudziyo wekumanikidza - Maturusi ekumanikidza akasiyana anoshandisa akasiyana algorithms kugadzira akasiyana mazinga ekumanikidza kwefaira. Mamwe maturusi ane mukurumbira ndiwo WinZip, zipX, 7-Zip uye WinRAR yevashandisi veWindows; Zvinhu X yevashandisi veMac; uye iZarc kune vakawanda-platform vashandisi.
3. Gadzirisa zvigadziriso zvekumanikidza - Kuti ugadzire mhedzisiro yakanyatsoenderana, ita zvigadziriso sekuchinja nhanho yekumanikidza, kugadziriswa kwemufananidzo kana mamwe akamisikidzwa marongero mukati mefomati yakamanikidzwa usati wamanikidza data. Tarisa zvakare muzvirongwa zvinogonesa mifananidzo yekutarisa pawebhu kana zvichibvira.
4. Dzvanya faira kana data - Tanga maitiro ekumanikidza nekudzvanya tanga kana "Zvakanaka" mukushandisa kwako kana wapedza nemagadzirirwo ako. Zvichienderana nehukuru hwemafaira ari kudzvanywa, zvinogona kutora maminetsi akati wandei kuti upedze kuita uku zvichienderana nekumhanya kwe processor uye software inoshandiswa.
5. Uncompress faira kana data - Iyo yekubvisa maitiro ichakubvumidza iwe kupinda kune ako achangobva shrunken mafaera kana apera kuitira kuti iwe ugone kutanga kuashandisa nekukasira asi akanyatsokodzera purojekiti yako iripo. Svika mafaera aunoda kubva kune akamanikidzwa maforodha mhando dzinowanzosiyana kubva .zip .rar .7z .tar .iso etc .. Unzip kudhirowa kuri kungotora chaiwo akamisikidzwa zvikamu kuburikidza nemaapplication akadai WinZip, 7Zip, IZarc etc .. kubvumira kudzora pachako pamusoro chii zvikamu zvaungade kusvikika chero nguva apo uchichengeta vamwe akaturikidzana akachengeteka zvakasimba akadzivirirwa folders zvichienderana zvaunofarira!

Maitiro Akanakisisa

Paunenge uchishandisa kurasikirwa kwekumanikidza, zvakakosha kushandisa chimiro chakakodzera chekushandisa chaiko. Semuenzaniso, kana iwe uchida kugovera faira remharidzo nevamwe vanhu, saka unofanirwa kushandisa a Yarasika mufananidzo fomati sezvo mharidzo dzinowanzo ratidzwa pane yakaderera resolution uye diki saizi.

Pane nzira dzakawanda dzekuwedzera kushanda kwekurasikirwa kwekumanikidza. Heano mamwe emaitiro akanakisa:

• Sarudza iyo yakakodzera compression fomati zvinoenderana nekese yako yekushandisa (jpeg yemifananidzo, mp3 yekuteerera, nezvimwewo).
• Seta nhanho yemhando yakakodzera zvichienderana nekuti ingani data raunoda kurasa.
• Rongedza ma parameter zvinoenderana nezvaunoda; ongorora kutengeserana pakati pehukuru hwefaira uye kunaka.
• Ziva kuti kushandisa lossy compression Kakawanda nguva inogona kupinza zvinhu zvinooneka mumafaira ako emidhiya uye kudzikisira kunaka kwavo zvinonyanya kukosha kupfuura kupasa kamwe kwekumanikidza kazhinji.
• Ita shuwa kuti metadata yakabatana nemafaira akadzvanywa yakachengetedzwa zvakanaka kuitira kuti ruzivo rwese rwakakosha rurambe rwuripo pakugovera kana kuratidza zvinhu zvemukati zvefaira.

mhedziso

Mukupedzisa, kurasikirwa kwekumanikidza inzira yakanaka yekudzikisa saizi yefaira uye kuderedza kurodha nguva pawebhusaiti uchiri kuchengeta a yepamusoro yehutano. Inokubvumira kuderedza saizi yefaira yemufananidzo kana odhiyo faira pasina kukanganisa kukuru pamhando yefaira. Zvakakosha kuyeuka, zvisinei, kuti kurasikirwa kwekumanikidza zvicharamba zvichikanganisa kunaka kwefaira uye inofanira kushandiswa nekuchenjerera.

Pfupiso yeLossy Compression

Kurasikirwa kwekumanikidza imhando yekudzvanya data inoderedza saizi yefaira nekubvisa mamwe eruzivo rwuri mufaira rekutanga. Maitiro aya anowanzo konzera mafaera ari madiki pane ekutanga mafaera uye akatsikirirwa uchishandisa algorithms akadai JPEG, MP3 uye H.264 kungotaura vashoma. Kurasika kudzvanya matekiniki anowanzo tengesa imwe mhando yehukuru asi yakagadziridzwa algorithms inogona kuburitsa mafaera ane mudiki mutsauko unoonekwa kubva kune isina kudzvanywa yepakutanga.

Paunenge uchiisa kurasikirwa kwekumanikidza, zvakakosha kuti utarise kuti yakawanda sei mhando ichagamuchirwa kune yakapihwa faira yekudzikisa saizi chinangwa. Kumwe kurasikirwa kwekumanikidza kunogona kuderedza saizi yemafaira zvakanyanya uku ichipa kurasikirwa kwemhando shoma nepo vamwe vachigadzira madiki mafaira asi nekukanganisa kusingagamuchirwe kana zvigadzirwa. Kazhinji, kana kuderedzwa kukuru kwehukuru kuchidikanwa, ipapo kurasikirwa kwemhando yakakura kunogona kutarisirwa uye zvakasiyana.

Pakazara, kurasikirwa kwekumanikidza kunopa nzira inoshanda yekudzikisa saizi yefaira pasina kupira kuita kwakawanda kana ichienzaniswa neyakaomeswa mafomu mumamiriro mazhinji; zvisinei, matambudziko aya anofanira kuongororwa pane imwe nyaya-ne-kesi hwaro asati aita sarudzo pamusoro pekuti kana kwete iyo mhinduro yakakodzera kune yakapihwa dambudziko rakaiswa.

Zvakanakira Kushandisa Lossy Compression

Kurasika kudzvanya kunopa akawanda mabhenefiti kudhijitari midhiya mafaera. Iyo yakanyanya kunaka mukana ndeyekuti kurasikirwa kwekumanikidza kunopa yakakura dhigirii re kuderedza saizi yefaira kupfuura zvetsika kusarasikirwa kwekumanikidza algorithms. Izvi zvinobatsira kuchengetedza kuchengetedza uye bandwidth zvinodiwa pazvishoma kana uchiendesa mahombe midhiya mafaera painternet, kana kuamanikidza kuti achengetere munharaunda.

Pamusoro pekupa zvirinani kudzikisa saizi yefaira pane echinyakare asina kurasikirwa maitiro, kushandiswa kwekurasikirwa kwekumanikidza kunoitawo kuti zvibvire kudzikisa saizi yemafaira zvakatowedzera uchiri kuchengetedza nhanho inogamuchirwa yemhando (zvichienderana nerudzi rwemidhiya iri kumanikidzwa). Uyezve, kushandisa kurasikirwa algorithms kunobvumira vashandisi kuita gadzirisa mufananidzo nemhando yekuteerera munharaunda sezvinodiwa pasina kudzoreredza faira rese - izvi zvinoita kuti kuchengetedza mafaera epurojekiti kuve nyore uye nekukurumidza sezvo zvikamu chete zvefaira remidhiya zvinoda kugadziridzwa.

Pakupedzisira, kushandisa kurasikirwa algorithms kunogona kupawo kuchengetedzwa kwakawedzerwa mune dzimwe nguva; sezvo redhiyo yepasi yebitrate isinganyanye kusiyanisa uye yakanyanya kuoma kududzira zvakafanana kana ichienzaniswa neshanduro dzepamusoro dzebitrate, inogona kupa imwezve chengetedzo kana maseti makuru edata achida kuchengetedzwa kubva mukuteerera kusingatenderwe kana kuona. Lossy compression's akawanda mabhenefiti ita kuti ive yakakurumbira pakati pevashandisi vedhijitari vanoda madiki mafaira nekuedza kushoma.

Mhoroi, ndini Kim, amai uye munhu anofarira zvekumira-famba ane ruzivo mukugadzira midhiya nekuvandudzwa kwewebhu. Ndine chido chikuru chekudhirowa uye mifananidzo, uye ikozvino ndiri kunyura nemusoro munyika yekumira-kufamba. Neblog rangu, ndiri kugovera zvandinodzidza nemi varume.