Kodi Lossless Compression ndi chiyani?<\/h3>\n
Kuponderezana kopanda kutaya kumachepetsa kukula kwa fayilo pozindikira ndikuchotsa kuchulukitsa kwa ziwerengero popanda kuchotsa chidziwitso chilichonse. Ikadetsedwa, fayiloyo imakhala yofanana pang’ono ndi yoyambayo, popanda kutayika konse mumtundu kapena kukhulupirika kwa data.<\/p>\n <\/div>\n <\/div>\n \n
Momwe Compression Yosataya Imagwirira Ntchito<\/h3>\n
Ma algorithms ophatikizika osatayika amagwiritsa ntchito njira zosiyanasiyana kuti achepetse kukula kwa mafayilo ndikuwonetsetsa kukonzanso bwino kwazomwe zidayambira. Njirazi zimasanthula machitidwe, ma frequency, ndi kapangidwe ka data kuti isungidwe bwino popanda kutaya zambiri.<\/p>\n \n
Run-Length Encoding (RLE)<\/h4>\n
RLE imalowa m’malo mwa kutsatizana kwa data yofanana (kuthamanga) ndi mtengo umodzi ndi kuwerengera. Mwachitsanzo, “AAAAAABBBCCCCC” imakhala “6A3B5C”, kuchepetsa kwambiri kukula kwa deta ndi maulendo obwerezabwereza.<\/p>\n
Original: WWWWWWWWWWBBBWWWWWWWWWWWWBBBWWWWWWWWWW\nCompressed: 10W3B12W3B10W<\/pre>\n <\/div>\n <\/div>\n \n\n\n <\/i>\n <\/div>\nHuffman Coding<\/h4>\n
Njira imeneyi imagawira zizindikiro zautali wosiyanasiyana kwa zilembo zolowetsa, ndi zizindikiro zazifupi za zilembo zomwe zimachitika kawirikawiri. Njira yowerengera iyi imakonzekeretsa kabisidwe kutengera kugawa pafupipafupi kwa zilembo.<\/p>\n
\n Chitsanzo:<\/strong>\nFrequent character 'e': 101\nLess frequent 'z': 1010101011<\/pre>\n <\/div>\n <\/div>\n \n\n\n <\/i>\n <\/div>\nZolemba za LZ77 & LZ78<\/h4>\n
Njira zotengera mtanthauzira mawuwa m’malo mwa kubwerezabwereza kwa deta ndikulozera ku buku limodzi lomwe likupezeka kale mumtsinje wosakanizidwa. Amapanga maziko amitundu yotchuka ngati ZIP ndi GIF.<\/p>\n
\n Chitsanzo:<\/strong>\nInstead of storing \"compression compression\"\nStore \"compression [pointer to earlier instance]\"<\/pre>\n <\/div>\n <\/div>\n \n\n\n <\/i>\n <\/div>\nChotsani algorithm<\/h4>\n
Kuphatikiza LZ77 ndi Huffman coding, Deflate imapereka kuponderezana kwabwino kwambiri ndi liwiro labwino. Imagwiritsidwa ntchito mu ZIP, PNG, ndi HTTP compression (gzip), ndikupangitsa kuti ikhale imodzi mwama algorithms omwe amagwiritsidwa ntchito kwambiri.<\/p>\n
\n Mapulogalamu:<\/strong>\n\n
- Zip archives<\/li>\n
- Zithunzi za PNG<\/li>\n
- HTTP compression (gzip)<\/li>\n <\/ul>\n <\/div>\n <\/div>\n \n
\n\n <\/i>\n <\/div>\nArithmetic Coding<\/h4>\n
Njirayi ikuyimira uthenga monga chiwerengero cha manambala pakati pa 0 ndi 1. Ikhoza kukwaniritsa ma compression ratios pafupi ndi malire a theoretical entropy, ndikupangitsa kuti ikhale yothandiza kwambiri pamitundu ina ya deta.<\/p>\n
\n Ubwino:<\/strong>\nItha kuyika ma bits ang’onoang’ono pachizindikiro chilichonse, chopatsa mphamvu kuposa Huffman pamagwero ambiri.<\/p>\n <\/div>\n <\/div>\n \n
\n\n <\/i>\n <\/div>\nDelta Encoding<\/h4>\n
M’malo mosunga zinthu zonse zofunika, delta encoding imasunga kusiyana pakati pa mfundo zotsatizana. Izi ndizothandiza makamaka pa data yomwe milingo yoyandikana nayo ili yofanana, monga zitsanzo zamawu kapena zowerengera za sensa.<\/p>\n
\n Chitsanzo:<\/strong>\nOriginal: 105, 107, 106, 110, 108\nDelta: 105, +2, -1, +4, -2<\/pre>\n <\/div>\n <\/div>\n <\/div>\n \nCommon Lossless File Formats<\/h3>\n
\n\n\n <\/i>\nZosungidwa zakale<\/h4>\n <\/div>\n
\nZIP<\/div>\nRAR<\/div>\n7Z<\/div>\nGZIP<\/div>\nBZIP2<\/div>\nTAR<\/div>\n <\/div>\n <\/div>\n \n\n\n <\/i>\nZithunzi<\/h4>\n <\/div>\n
\nPNG<\/div>\nTIFF<\/div>\nBMP<\/div>\nGIF<\/div>\nWebP (yosataya)<\/div>\n <\/div>\n <\/div>\n \n\n\n <\/i>\nZomvera<\/h4>\n <\/div>\n
\nFLAC<\/div>\nChithunzi cha ALAC<\/div>\nWAV<\/div>\nAPE<\/div>\nWavPack<\/div>\n <\/div>\n <\/div>\n <\/div>\n <\/div>\n <\/section>\n \n \n\n Kutaya Kupanikizika Kufotokozera<\/h2>\n \n
\n\n\n <\/i>\n <\/div>\n\nKodi Lossy Compression ndi chiyani?<\/h3>\n
Kuphatikizika kotayika kumachepetsa kukula kwa fayilo ndikuchotsa zidziwitso zina, makamaka zosafunikira kapena zosafunikira kwenikweni. Fayilo yowonongeka ndi yosiyana ndi yoyambirira, koma kusiyana kwake kunapangidwa kuti zikhale zovuta kapena zosatheka kuti anthu azindikire pansi pazochitika zabwino.<\/p>\n <\/div>\n <\/div>\n \n
Momwe Lossy Compression Imagwirira Ntchito<\/h3>\n
Kuponderezana kotayika kumapangitsa kuti pakhale ma compression apamwamba kwambiri popanga zisankho zanzeru zomwe mungatayire. Ma aligorivimuwa amapititsa patsogolo chidziwitso chokhudza malingaliro a anthu – zomwe maso athu ndi makutu athu amatha kuzindikira komanso zomwe sangathe kuzizindikira – kuchotsa chidziwitso m’njira zochepetsera kukhudza kowoneka bwino.<\/p>\n \n
\n\n\n <\/i>\n <\/div>\nKusintha Coding<\/h4>\n
Njirayi imasintha deta kuchokera ku dera lina (monga malo) kupita ku lina (monga mafupipafupi) kumene kuponderezana kungagwiritsidwe ntchito bwino. Discrete Cosine Transform (DCT) yogwiritsidwa ntchito mu JPEG ndi chitsanzo chabwino.<\/p>\n
\n Njira:<\/strong>\n\n
- Sinthani midadada ya zithunzi kukhala magawo afupipafupi<\/li>\n
- Chepetsani zigawo za ma frequency apamwamba kwambiri<\/li>\n
- Maso aumunthu sakhudzidwa kwambiri ndi ma frequency awa<\/li>\n <\/ul>\n <\/div>\n <\/div>\n \n
\n\n <\/i>\n <\/div>\nQuantization<\/h4>\n
Quantization imachepetsa kulondola kwamitengo ya data. Imayika mayendedwe osiyanasiyana kumagulu ang’onoang’ono otulutsa, kuchepetsa bwino kuchuluka kwa ma bits ofunikira kuyimira deta.<\/p>\n
\n Chitsanzo:<\/strong>\nOriginal values: 4.13, 4.28, 4.97, 4.02\nQuantized to: 4, 4, 5, 4<\/pre>\n <\/div>\n <\/div>\n \n\n\n <\/i>\n <\/div>\nPsychoacoustic Modelling<\/h4>\n
Njirayi imagwiritsidwa ntchito popanikiza mawu, imagwiritsa ntchito kulephera kwa kumva kwa anthu. Imazindikiritsa kuti ndi zigawo ziti zamawu zomwe zitha kuchotsedwa popanda kukhudza mtundu wa mawu omwe akumveka.<\/p>\n
\n Mfundo zazikuluzikulu:<\/strong>\n\n
- Kuphimba makutu: Kumveka mokweza kumamveka ngati chigoba chopanda phokoso<\/li>\n
- Frequency sensitivity: Anthu amamva ma frequency apakati bwino kwambiri<\/li>\n
- Kuphimba kwakanthawi: Kumveka kumatha kubisa zina zomwe zimachitika patangopita nthawi pang’ono \/ pambuyo pake<\/li>\n <\/ul>\n <\/div>\n <\/div>\n \n
\n\n <\/i>\n <\/div>\nPerceptual Coding<\/h4>\n
Mofanana ndi psychoacoustic modeling koma kwa deta yowonekera, njirayi imachotsa chidziwitso chomwe maso aumunthu sangazindikire, makamaka mwatsatanetsatane wafupipafupi komanso kusiyana kwa mitundu.<\/p>\n
\n Mapulogalamu:<\/strong>\nAmagwiritsidwa ntchito mu JPEG, MPEG, ndi milingo ina yowoneka bwino kuti ikhazikitse deta yofunika kwambiri.<\/p>\n <\/div>\n <\/div>\n \n
\n\n <\/i>\n <\/div>\nMalipiro Oyenda<\/h4>\n
Njira yophatikizira makanema yomwe imagwiritsa ntchito kubwezeredwa kwakanthawi polemba kusiyana pakati pa mafelemu m’malo mwa chimango chilichonse. Zosintha zokha kuchokera pa chimango chimodzi kupita kwina ndizokhazikika.<\/p>\n
\n Njira:<\/strong>\n\n
- Sungani “makeyframes” athunthu (I-mafelemu) nthawi ndi nthawi<\/li>\n
- Pamafelemu ena, sungani kusiyana kokha (mafelemu a P) kapena kusiyana kwa wirirectional (B-mafelemu)<\/li>\n
- Zotsatira zakuchepetsa kukula kwa mafayilo amakanema<\/li>\n <\/ul>\n <\/div>\n <\/div>\n \n
\n\n <\/i>\n <\/div>\nChroma Subsampling<\/h4>\n
Njira imeneyi imachepetsa chidziwitso cha mitundu kuposa chidziwitso chowala, kugwiritsa ntchito mwayi wamaso amunthu kuti azitha kumva kuwala kuposa kusiyanasiyana kwamitundu.<\/p>\n
\n Mawonekedwe Odziwika:<\/strong>\n\n
- 4:4:4 – Palibe subsampling (mtundu wathunthu)<\/li>\n
- 4:2:2 – Magawo opingasa amitundu<\/li>\n
- 4:2:0 – Imagawaniza mitundu yopingasa komanso yoyima<\/li>\n <\/ul>\n <\/div>\n <\/div>\n <\/div>\n \n
Common Lossy File Formats<\/h3>\n
\n\n\n <\/i>\nZithunzi<\/h4>\n <\/div>\n
\nJPEG<\/div>\nWebP (yotayika)<\/div>\nJPEG 2000<\/div>\nHEIF<\/div>\nAVIF<\/div>\n <\/div>\n <\/div>\n \n\n\n <\/i>\nZomvera<\/h4>\n <\/div>\n
\nMP3<\/div>\nAAC<\/div>\nVorbis<\/div>\nOpus<\/div>\nWMA<\/div>\n <\/div>\n <\/div>\n \n\n\n <\/i>\nKanema<\/h4>\n <\/div>\n
\nH.264<\/div>\nH.265<\/div>\nVP9<\/div>\nAV1<\/div>\nWebM<\/div>\n <\/div>\n <\/div>\n <\/div>\n <\/div>\n <\/section>\n \n \n\n Zochita Zothandiza ndi Zogwiritsa Ntchito<\/h2>\n \n
\n\n\n\n <\/i>\n <\/div>\nZithunzi za digito<\/h3>\n <\/div>\n
\nKuponderezana Kosataya<\/h4>\n
\n
- Kusungidwa kwa mawonekedwe a RAW kwa akatswiri ojambula<\/li>\n
- Kusungidwa kwabwino kwa zithunzi zofunika<\/li>\n
- Zithunzi zomwe zimafuna zambiri pambuyo pokonza kapena kusintha<\/li>\n
- Mtundu wa PNG wazithunzi zokhala ndi mawu kapena m’mbali zakuthwa<\/li>\n <\/ul>\n \n
Kutaya Compression<\/h4>\n
\n
- JPEG ya zithunzi zatsiku ndi tsiku komanso kugawana pa intaneti<\/li>\n
- Kupanga zithunzi zamagalasi ndi zowoneratu<\/li>\n
- Kuyika kwapa social media komwe kuli malire<\/li>\n
- Kutumiza kwa imelo ndi ntchito zotumizira mauthenga<\/li>\n <\/ul>\n \n
\n Kuchita Bwino Kwambiri:<\/strong> Jambulani mu RAW kapena mtundu wosatayika, pangani mitundu yotayika kuti mugawane, sungani ambuye osatayika kuti musungidwe.\n <\/div>\n <\/div>\n <\/div>\n \n\n\n\n <\/i>\n <\/div>\n