Huffman zizindikiro: Zitsanzo ntchito

Pa nthawi, anthu ochepa kuganizira mfundo, kodi file psinjika. Poyerekeza ndi kugwiritsa ntchito m'mbuyomu a kompyuta munthu wakhala zambiri mosavuta. Ndipo pafupifupi munthu aliyense ntchito ndi dongosolo file amagwiritsa owona. Koma anthu ochepa kuganizira mmene ntchito ndipo maziko chiyani file psinjika. Baibulo loyambirira la ndondomeko kunali zizindikiro Huffman, ndipo ntchito lero zosiyanasiyana archivers otchuka. owerenga ambiri n'komwe n'zosavuta file psinjika chikuchitika ndipo akugwira ntchito pa ndale. M'nkhani ino tidzamva mmene psinjika ndi zimene mokoma thandizo msanga ndi zinthu zochepa ndondomeko kabisidwe, komanso kuona zomwe mfundo ya 'kala' ikusonyeza mtengo.

History aligorivimu

The aligorivimu choyamba cha imayenera 'kala' ikusonyeza za mfundo pakompyuta wakhala kachidindo Huffman akufuna mwamsanga pakati pa mazana makumi awiri, ndicho mu 1952. Zinali iye amene pa nthawi ndi zinthu m'munsi mwa ambiri mapulogalamu analengedwa kuti compress mfundo. Pa nthawi, gwero lina la anthu otchuka ntchito m'ndondomekozi ndi yachokera ZIP, ARJ, rar ndi ena ambiri. Komanso aligorivimu Huffman ntchito compress JPEG-zithunzi ndi zinthu zina zojambulajambula. Chabwino, mauthenga a fakisi onse komanso ntchito 'kala' ikusonyeza ano, anatulukira mu 1952. Ngakhale kuti kuyambira chilengedwere code anatenga nthawi yayitali kuti tsiku limeneli ntchito zosiyanasiyana zimagwira ntchito zosiyanasiyana zatsopano ndi zida akale ndi amakono mitundu.

Mfundo 'kala' ikusonyeza imayenera

Maziko a Huffman aligorivimu zikuphatikizapo chiwembu kuti amalola kuti m'malo ambiri zodalirika, nthawi zambiri zikuchitika zizindikiro yosiyanasiyana bayinare dongosolo. Ndipo amene sakhala wamba, m'malo ndi zizindikiro yaitali. Kupita Kutsatsa yaitali Huffman amapezeka pokhapokha dongosolo amagwiritsa makhalidwe onse osachepera. Njira imeneyi zimathandiza inu kuchepetsa kutalika code lililonse chizindikiro cha Uthenga wapachiyambi wonse. Mfundo n'kofunika kuti pa chiyambi cha 'kala' ikusonyeza Mwina yatsoka makalata ayenera kale. Ndi kwa iwo adzakhala okonzeka ndi uthenga womaliza. Yachokera pa kafukufuku izi, anagwira pomanga Huffman malamulo mtengo, pa maziko amene udzachitike makalata kabisidwe njira zakale za.

Huffman code, Mwachitsanzo

Kuti timvetse aligorivimu, taonani zosinthika mawonekedwe a yomanga mtengo code. Kugwiritsa ntchito njira imeneyi kuti azigwira, m'pofunika kuti anthu amvetse tanthauzo la mfundo zina zofunika mfundo za ndondomeko. Achikhalire za kuchuluka kwa mfundo ndi arcs, amene akuuzidwa kuchokera mfundo ndi mfundo, wotchedwa Zithunzi. Mtengo pawokha ndi Zithunzi ndi mndandanda wa katundu chindunji:

• aliyense mfundo zingaphatikizepo zosaposa mmodzi wa arcs;
• mmodzi wa mfundo ayenera muzu wa mtengo, ndiko kuti, asakhale wa Arc pa onse;
• ngati tsinde anayamba kuyendera arcs ndi ndondomeko ayenera kulola kuti kwathunthu mu iliyonse ya mfundo za.

Palinso chinthu choterocho, mbali ya zizindikiro ndi Huffman ngati tsamba la mtengo. Ndi mfundo imene sayenera Arc iliyonse. Ngati mfundo ziwiri ogwirizana ndi Arc, ndipo mmodzi wa iwo ndi makolo a mwana zina, malingana ndi kumene mfundo Arc uchoka, ndi zimene zili m'gulu. Ngati mfundo ziwiri chimodzimodzi kholo mfundo, iwo amatchedwa malo mlongo. Ngati, mu masamba, masamba ku mfundo ya arcs angapo, ndiye amatchedwa mtengo bayinare. Momwemo ndi mtengo Huffman. The peculiarity wa zomangamanga mayunitsi ndi kulemera kwa kholo lililonse ndi wofanana Uwerenge zolemera za ana ake onse mfundo.

An aligorivimu kumanga mtengo Huffman

Popanga malamulo Huffman ndi athandizira ku zilembo. Kwaiye mndandanda wa malo amene angathe mtengo malamulo m'tsogolo. Kulemera kwa aliyense mfundo mu mndandanda ayenera mofanana Mwina wa zosayembekezereka ya zilembo posts lolingana mfundo imeneyi. Pankhaniyi, amene akulemera chaching'ono ndi osankhidwa mwa malo angapo ufulu wa mtengo m'tsogolo. Pankhaniyi, ngati mitengo osachepera ali anati mu malo angapo, inu momasuka kusankha aliyense wa awiriawiri lapansi. Pamenepo adadzanso chilengedwe cha kholo mfundo, amene ayenera kuganizira momwe Uwerenge zolemera za nsapato mfundo. Pambuyo pake, makolo kutumiza mndandanda ndi chimbudzi free, ndi ana amachotsedwa. Mu Arc izi ndi zizindikiro zoyenera, anthu ndi maziro. Zimenezi mobwerezabwereza mmene anayenera kukhala yekha ndi mfundo limodzi. Kenako lembani mu manambala bayinare kuchokera pamwamba mpaka pansi.

Kuwonjezera pa dzuwa la psinjika

Pofuna kuonjezera psinjika dzuwa, m'pofunika pa mtengo nyumbayi Code kugwiritsa ntchito deta onse pa Mwina wa zosayembekezereka ya zilembo wapamwamba makamaka Ufumuyo mtengo, ndipo sadzalola chakuti iwo anamwazikana ambiri zikalata malemba. Ngati chisanadze kuyenda kupyolera file ichi, inu athanso kuwerengera ziwerengero kangati pali makalata a nkhani malo kuti psinjika a.

Mofulumira za ndondomeko psinjika

Mofulumira aligorivimu, tanthauzo la makalata zizichitidwa osati mwa mawu a Mwina yatsoka la kalata makamaka, ndipo pafupipafupi pakuwonekera kwake. Ndi aligorivimu imeneyi kumakhala kosavuta, ndi kugwira ntchito ndi iwo mofulumira kwambiri. izo amapewanso ntchito kugwirizana ndi gulu akuyandama-mfundo. Komanso, ntchito mu mode ichi, mphamvu Huffman code, kapena nditi aligorivimu pakokha ungasinthe iliyonse. Izi zili choncho makamaka chifukwa chakuti ziyerekezo ndi mwachindunji njila kwa pafupipafupi. M'pofunikanso powasamalira chakuti kulemera lomaliza la wapamwamba, kapena otchedwa muzu mfundo ndi wofanana Uwerenge chiwerengero cha anthu a chinthu kuchitiridwa.

Pomaliza

zizindikiro Huffman - losavuta ndi kuleza anakhazikitsa aligorivimu, amene adakali ntchito ndi mapulogalamu ambiri odziwika ndi makampani. kuphweka ake kumva akhoza kukwaniritsa zotsatira ogwira compress owona a buku lililonse ndi kuchepetsa mpata pa yosungirako litayamba. Mu mawu ena, Huffman aligorivimu - wachita kale ankafufuza ndi ntchito chithunzi chimene mwamsanga osati kuchepetsedwa ndi tsiku lino. Ndipo ndi luso kuchepetsa kukula kwa owona, kusamutsa iwo pa Intaneti kapena zina amatanthauza ndi wosavuta kudya ndi yabwino. Kugwira ntchito ndi aligorivimu, mukhoza compress mfundo iliyonse kwathunthu popanda vuto dongosolo ake ndi quality, koma ndi zotsatira pazipita kuchepetsa kulemera file. Mu mawu ena, 'kala' ikusonyeza pa malamulo Huffman wakhala ndi kukhala njira wotchuka kwambiri ndi zogwirizana wa compressing kukula file.