Resolution and Color Model

 

Scanner

Digital Camera

Monitor/TV

Desktop Printer

Press

Bit Measurement

spi (samples per inch)

dpi

ppi (pixels per inch)

dpi (dots per inch)

lpi (lines per inch)

Typical
Resolution

600 flatbed
400 handheld

600 capture;
final output 640x480 pixels

72 or 75;
screen setting in pixels divided by monitor size

300 to 600

1200 +

Color Model

RGB, bitmap

RGB

RGB

RGB

CMYK

 

Common Image Formats

Image

Format

Extension

Where Used

Color, Grayscale,

Bitmap:
up to millions of colors


indexed color

up to millions of colors


TIF, TIFF*

BMP, PCX, PICT

GIF

JPG, JPEG


printing press

on-screen

internet

internet

 

Object oriented: up to millions of colors

EPS


WMF

Postscript printer
printing press

desktop printer

Line Art

bitmap, 1 bit

BMP, PCX, PICT

on-screen
desktop printer

*Hint: Three letter extension means PC format, four letter extension means MAC format.

 

Color Bit Depth

Bit Depth

Color

Distribution

Image Type

1

No

Black and White
21

Line art

Halftone

8

No

256

Black, 254 shades of Gray, White

Palette limited to Black*, 10 shades of Gray, White*, and 214 colors.
28

Grayscale

Indexed color

24

millions

256 shades each of Red, Green, and Blue*
(28)3

Full color

 
* Black = R0, G0, B0   White = R255, G255, B255

© Donna Ford 2000