RASTER GRAPHICS
2.01 Understand Digital Raster Graphics
RASTER GRAPHICS
Also called bitmap
graphics
 Consist of grids of tiny
dots called pixels
 Have a fixed resolution
and cannot be resized
without altering image
quality
 Edited in paint programs

RASTER GRAPHICS
Can support high color depths.
 Most common type of raster is a digital
photograph.
 Great for adding special effects.
 Work well for web design.
 Used to create images for print design.
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RASTER GRAPHICS

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Native File Formats: file formats that are default file
format that are proprietary to a specific program that
are generally not meant to be used with other
software.
Standard File Formats: file formats that can be used
with a variety of software programs. Standard file
formats are usually created by using the “Save As”
command or through exporting. Standard file formats
include, but are not limited to: .gif, .jpg, .png, and .tif.
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COMMON RASTER FORMATS
PSD
PNG
JPEG
TIFF
GIF
PDF
1.01 Investigate graphic types and file formats.
PSD – PHOTOSHOP DOCUMENT

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Native file format for
Adobe Photoshop
Supports transparency
Supports layers, text,
and effects
Large file sizes.
Industry standard for
raster graphic editing
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GIF – GRAPHICS INTERCHANGE
FORMAT

 Most common format for:
Standard format for
animation on the Internet  Text

Supports transparency

Lossless compression

Colors = 256 (8-bit)





Clip art, animations, icons,
logos
Simple diagrams, line
drawings
Graphics with large blocks
of a single color
Graphics with transparent
areas
Images displayed on
computer screens and on
websites.
JPEG – JOINT PHOTOGRAPHIC EXPERTS GROUP
X
X


Does not support
animation or
transparency
Lossy compression.
Colors – 16.7 M (24-bit)
High quality

Commonly Used For:





Desktop publishing
photographs
Photographs and natural
artwork
Scanned photographs
Emailing photographs
Digital camera photographs
PNG – PORTABLE NETWORK GRAPHICS
X


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Does not support
animation

Commonly Used For:

Supports transparency
Lossless compression
Supports multiple color
depths

PNG 8 – 8 bit color


Small Graphics
PNG 24 – 24 bit color

Basic Graphics


Replacing GIF and TIFF
images
Online viewing of images
See examples at
http://graphicssoft.about
.com/od/freedownloads/
l/blfreepng07.htm
TIFF – TAGGED IMAGE FILE FORMAT
X



Does not support
animation or
transparency
Available in compressed
(lossless) and uncompressed formats
Compressed is advised
Colors – 16 M (24-bit)

Commonly Used For:



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Storage container for
faxes and other digital
images
To store raw bitmap data
by some programs and
devices such as scanners
High resolution printing
Desktop Publishing
images
1.01 Investigate graphic types and file formats.
PDF – PORTABLE DOCUMENT FORMAT
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Open source, platform
independent format that
embeds fonts, images,
layouts, and graphics
Allows choice of lossy and
lossless compression
Supports 16 million colors
Viewable with Acrobat
Reader, a free program by
Adobe

Commonly used for:



Sharing files regardless of
available software
Share files that can be
protected from copying or
editing
Publishing electronic
documents and ebooks
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