Khoos phib tawj Graphics: xim tob

Rau hnub tim technology thiab cov khoom siv cia rau ua thiaj kaj lug thiab tiag tiag li duab uas nws yuav ua tau ntau heev tshaj dua zoo nkauj dua nws tiag tiag chiv keeb. Qhov zoo tshaj ntawm cov kis duab nyob rau hauv ob peb yam tseem ceeb: tus xov tooj ntawm megapixels, duab loj, cov duab loj thiab thiaj li nyob. Cov no muaj xws lwm vaj tse - cov xim tob. Yuav ua li cas yog nws, thiab yuav ua li cas txhais tau thiab xam?

Txheej txheem cej luam

Xim tob - lub siab tshaj plaws pes tsawg tus ntawm ntxoov ntawm cov xim uas yuav tsuas muaj cov duab. Qhov no kom muaj nuj nqis yog ntsuas nyob rau hauv me me (tus naj npawb ntawm cov binary khoom uas txiav txim cov xim thiab cov Hawj txawm ntawm txhua pixel nyob rau hauv ib tug raster graphics duab). Piv txwv li, ib tug pixel, cov xim tob yog sib npaug zos rau 1 ntsis tej zaum yuav xav tias ob qhov tseem ceeb: dawb thiab dub. Thiab qhov ntau tseem ceeb yuav tsum tau cov xim tob, cov duab yuav tsum varied, muaj ib tug plurality ntawm cov xim thiab ntxoov. Nws tseem yog lub luag hauj lwm rau cov duab fidelity. Ntawm no, txhua yam yog tib txoj kev: lub siab, lub zoo dua. Raws li lwm cov piv txwv, GIF hom daim duab nrog ib tug xim tob ntawm 8 me me, yuav muaj 256 xim, thaum JPEG hom duab nrog ib tug tob ntawm 24 khoom yuav muaj xws li 16 lab xim.

Ib me ntsis ntawm RGB thiab CMYK

Feem ntau, tag nrho cov ntawm cov duab cov ntaub ntawv tawm tswv muaj ib cov xim tob ntawm 8 khoom ib muaj ib tug channel (xim). Tab sis nyob rau hauv daim duab tej zaum yuav tam sim no, thiab ntau yam xim raws. Ces twb yog nqus RGB peb raws yuav muaj ib tug tob ntawm 24 khoom (3h8). Tob CMYK xim dluab yuav ua tau mus 32 me me (4x8).

Tiam sis ib tug me ntsis

Cov xim tob - lub xov tooj ntawm ntxoov ntawm tib xim, uas ntaus ntawv rau hauv kev sib cuag nrog cov dluab, yuav muaj me tub los yog tsim. Qhov no parameter yog lub luag hauj lwm rau cov tus hloov ntawm ntxoov nyob rau hauv cov dluab. Tag nrho cov dluab encoded los ntawm txoj kev sawv daws yuav thiab zeros. Xoom - dub, Unit - Dawb. Muab cia thiab khaws cia lawv nyob rau hauv lub cim xeeb yog ntsuas nyob rau hauv bytes. Ib tug byte muaj 8 me me, uas yog denoted thiab xim tob. Rau cov koob yees duab, muaj lwm cov lus txhais ntawm lub matrix yog qhov tob ntawm cov xim. Qhov no yog ib qho uas qhia hais tias txiav txim raws li qhov uas tus puv thiab sib sib zog nqus duab nyob rau hauv cov nqe lus ntawm ntxoov thiab xim muaj peev xwm tsim ib tug lub koob yees duab, thiab ntau yeej nws matrix. Vim lub high nqi ntawm no parameter, cov duab yog loj thiab du.

daim ntawv tso cai

Qhov link ntawm cov xim tob thiab daim duab zoo yog nws daws teeb meem. Piv txwv li, 32-ntsis duab nrog ib tug daws teeb meem ntawm 800x600 yog ho mob heev ntxiv dua nrog zoo xws li cov 1440x900. Tseeb, nyob rau hauv lub thib ob cov ntaub ntawv nws muab kev koom tes ib tug loj npaum li cas naj npawb ntawm cov pixels. Qhov no yog heev yooj yim yuav ua rau koj tus kheej. Txhua yam koj yuav tau ua - yog mus rau lub PC nyob rau hauv lub "Duab haum" thiab sim li qhia siv kuj txo los yog nce rau hauv lub screen daws teeb meem. Thaum lub sij hawm tus txheej txheem no, koj yuav kom meej meej tseeb ntau npaum li cas cov kev daws teeb meem muaj feem xyuam rau qhov zoo ntawm cov kis dluab. Tsis hais txog ntawm yuav ua li cas muaj ntau yam xim muaj xws li ib tug kev duab, nws yuav muaj mus rau ib tug nqi siab tshaj plaws uas muaj peev xwm sawv ntawm txhawb ib tug saib. Raws li ib qho piv txwv peb yuav noj saib nrog 16 me ntsis xim tob thiab daim duab nrog 32 me me. Qhov no duab nyob rau saib yuav tso saib xws li ib tug 16 ntsis xim tob.