Picture Editing- Tutorial 1

Stuart Crump

Informations

• Publié par: Mafor
• Nombre de lectures: 36
• Langue: English

Extrait

PCCLUB.ORG.UK
rd
Tuesday, 3 May 2005
Stuart Crump
Picture Editing, Printing & Publishing
Pe ngnt sh
Tutorial 1 of 2
Ta 2Overview
Or
th
2 Sessions (today & 18 May)
Snda1ay
Tonight
o
– AAll abouut “Inpuutt” and ““Manipuullation”
Image formats, types and sizes, what’s best.
getsan, be
Tools, what to look for.
ls,o r.
Maniippulation,, cchangingg images ffoor the beettter!
th
t
18 May8y
– All about “Output” and “Sharing” Autpdin
Printing, what options do I have.
tint o de.
Sharing, different media for different occasions.
rinreiafecaImage formatsag f
How many image formats are there?
wnar th
– 10, 20, 30?0 3
– 50+ not including variants or “Vector” formats0tdar oc fos
– Some standard, but many proprietaryotard m pe
Why so many?
ym?
– Support different features of the productsut reat o pct
– Different media / outputintiatImage Types
You mentioned “Vector” what’s that?
utdct
Computer images can be categorised into
mrga co
2 types, Vector and Raster.y Vod t
– Vector is an image that is made up from eim t m um
lines, curves and flat colours.inuant r
Used lleess ofteen by hoome useerrs
– Raster is an image that is made up from dots aim t m ums
or pixels and multi-toned colours.rlsmoo.
Most widely used by home users
wus hus
– For example…omImage Types
What’s the difference?
aere
– Sizeiz
– Qualityu RASTER
– Audienceue
VECTORImage FormatsagF
3 main Raster formats
– RAW
The RAW image format is the data from a digital camera as it comes directly
off the CCD, with no in-camera processing performed. Resolution and
colours is not limited.
– JPG or JPEG (pronounced ‘jaypeg’)
Joint Photographic Experts Group. Common format for displaying images on
the Web. JFIF (JPEG File Interchange Format) is the actual file format used
to compress an image with the JPEG method which is a standard developed
for still-image compression sanctioned by the International Standards
Organization (ISO). Resolution is limited to 32-bits, or 16milion colours.
– GIF /GIF89a
Graphic Image File (GIF) format, a widely supported image-storage format
promoted by CompuServe that gained early widespread use on online
services and the Internet. Resolution is limited to 8-bits, or 256 coloursImage FormatsagF
You mentioned “Compression” how does
utdms hdo
that work on images?tkms
It’s unlike PKZip
eip
Not available on all image formats
t laonim a
Compression is “lossless”
msssl
– Affects the quality as well as file sizef tasasImage FormatsagF
1 main Vector formats
ainrs
– EPSP
Encapsulated PostScript (EPS) is a standard file format for importing and
lacr isrdatrti
exporting PostScript files. EPS files can be generated by all drawing g t f fil g bin
applications as well as most layout applications. Image manipulation ionl ayoatigeati
programss like Adobee PhotoShoopp can also ssaave bitmapp iimages ass EEPS-files.
Some printer drivers are also capable of generating EPS-files as well as rinrs capenEPS w
PostScript files. iptFormatting TipsmtiT
Keep a copy of the original “digital” file.
eofoai fi
– Previewing in Windows can alter the format.ri Wwn trm
Don’t worry about file size…just yet.
nrboilet
Use the file format of your software
e firmorw
– More about that laterbar
Use layers to preserve your work.
e rspvur
– Remember John’s tutorial…ebht
Vector is better when you need to resize.
ct rn sImage Sizesee
MegaPixels?
gals
– 5.1 MP Photo = ~2Mb file.1h ~fil
2048 x 1536 resolution
x 1so
Very good for a 5”x7” printed photo or bigger
oo 5rinotoge
– 3.2 MP Photo = ~1.3Mb file.2h ~b
– … that’s ~300 images per CD, ~2000 per DVD ~mpe ~p
– … or 0.7 images per floppy disk ;-) is pk
Scanned Images
nIms
– Much higher resolutionugho
Upwards of 3600x2400 resolution and 1200DPi
ds0re a0D
– Images can scale quickly to 10s of Mbsmcalelys s
My 3 yeear old sccaanner crreeates 80MMb files!