JPEG vs RAW
JPEG thiab RAW yog ob qho ntawm cov duab cov ntaub ntawv tawm tswv yim. Ntau yam raug cai, RAW yog hom duab cov ntaub ntawv uas tau ua tiav tsawg kawg nkaus thiab JPEG yog ib txoj hauv kev ntawm cov duab digital compression. Cov koob yees duab ua ntej txuag cov duab rau RAW hom ib ntus, thiab tom qab ntawd hloov mus rau JPEG siv qhov nyiaj tshuav dawb thiab lwm yam khoom siv hauv lub koob yees duab los ntawm tus neeg siv. Ces cov ntaub ntawv RAW feem ntau yog deleted.
RAW yog dab tsi?
A RAW cov ntaub ntawv yog hom ntaub ntawv rau cov duab cov ntaub ntawv uas muaj cov ntaub ntawv uas tau ua tiav tsawg. RAW cov ntaub ntawv muaj cov ntaub ntawv los ntawm cov koob yees duab digital, cov duab scanners lossis cov duab thaij duab uas tau txais cov tswv yim los ntawm cov duab sensors. RAW cov ntaub ntawv tau txais lawv lub npe vim tias cov ntsiab lus tsis ua tiav. Yog li, RAW cov ntaub ntawv tsis tsim nyog yuav tsum luam tawm lossis kho yam tsis tau ua. RAW cov ntaub ntawv feem ntau hu ua digital negatives (vim lawv zoo ib yam li cov negatives hauv kev yees duab yees duab). Ib yam li qhov tsis zoo, RAW cov ntaub ntawv tsis tuaj yeem siv ncaj qha los ua duab (tab sis lawv muaj tag nrho cov ntaub ntawv los tsim cov duab). Kev hloov dua siab tshiab ntawm cov ntaub ntawv nyoos yog hu ua kev tsim kho (dua piv rau kev txhim kho zaj duab xis).
Feem ntau yog los ntawm kev ua cov ntaub ntawv RAW siv qhov dav-gamut sab hauv xim, qhov tsim nyog hloov kho uas xav tau los hloov nws mus rau "zoo" cov ntaub ntawv tawm tswv yim (xws li TIFF lossis JPEG) lossis luam ntawv tuaj yeem ua tiav. Qhov no thaum kawg ua rau lub cuab yeej nyob ntawm colorspace. Txawm hais tias, tag nrho cov ntaub ntawv RAW yog categorically hu ua RAW duab cov ntaub ntawv, muaj ntau cov ntaub ntawv tawm tswv yim uas koom nrog tsev neeg no (xws li.3fr,.ari thiab.dcr). Cov ntaub ntawv sib txawv no yog siv los ntawm cov koob yees duab digital sib txawv. Lub hom phiaj ntawm kev muaj duab hauv RAW hom yog kom txo qis cov ntaub ntawv poob los ntawm cov ntaub ntawv muab rho tawm los ntawm cov duab sensor. Yog li ntawd, cov ntaub ntawv RAW feem ntau muaj ntau yam xim ntau dua li qhov kawg ntawm hom ntawv.
JPEG yog dab tsi?
JPEG yog ib txoj kev ntawm compression uas yuav siv tau los tsim lossy compressed cov duab. JPEG (Joint Photographic Experts Group) pab pawg tsim cov qauv no rau compression. Txhawm rau kom muaj kev sib haum xeeb ntawm qhov loj thiab qhov zoo, qhov degree ntawm compression tuaj yeem raug xaiv. Koj tuaj yeem ua tiav 10: 1 compression yam tsis tau poob ntau ntawm cov duab zoo. Ntau cov duab cov ntaub ntawv tawm tswv yim siv JPEG compression. Piv txwv li, JPEG / Exif cov duab cov ntaub ntawv yog siv los ntawm cov koob yees duab digital thiab JPEG / JFIF yog siv rau cov duab ntawm lub vev xaib. Tab sis tag nrho cov no yog hu ua JPEG cov ntaub ntawv yooj yim. Cov Mime hom duab / jpeg lossis duab / pjpeg tau tshwj tseg rau hom ntawv JPEG.
Qhov txawv ntawm JPEG thiab RAW yog dab tsi?
RAW yog hom duab tsis zoo, thaum JPEG yog hom duab zoo. JPEG yog hom ntawv universal, thaum RAW yog cov chaw tsim khoom nyob ntawm hom. Yog li ntawd, feem ntau mob siab rau software yuav tsum tau nyeem RAW cov ntaub ntawv. Tab sis txhua tus neeg saib duab tuaj yeem siv los saib cov ntaub ntawv JPEG. Yog li, yog tias koj coj koj cov duab hauv RAW hom, thiab koj tsis muaj cov software tshiab hauv lub computer, koj tsis tuaj yeem qhib cov ntaub ntawv. Qee zaum koj yuav xav tau yuav software qhib RAW cov ntaub ntawv (nyob ntawm cov ntaub ntawv qhov txuas ntxiv). Thiab rau kev tua, RAW tsis haum, vim RAW cov ntaub ntawv loj loj.
