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Subject:Re: Graphics Format Question From:"Walker, Arlen P" <Arlen -dot- P -dot- Walker -at- JCI -dot- COM> Date:Wed, 4 Feb 1998 09:51:52 -0600
Does anyone know where I could find some sort of list that explains
why you'd need a particular graphics format?
Most of the time, the reason you need a particular format is because the
application involved requires it.
Graphics formats can be broken down into two basic types, vector and
raster.
Raster formats are bit-maps, i.e., they contain information for each pixel
of the image. A line is reprsented by every point along it, and the images
have a fixed resolution. Vector graphics contain commands to draw
particular shapes, and include information about where to draw the shape
and what its
characteristics are. In these, A line is usually represented by start point
and end point, with information about thickness, pattern and color.
Raster formats have a specific resolution. They can be scaled up or down,
but errors and artifacts will occur as you scale them. Vector graphics
scale quite well to a wide range of resolutions. Natively, vector graphics
usually
make for smaller files than raster, but raster files compress more easily
and efficiently. Vector graphics files will usually display and print
faster, though if no scaling is required raster images may be faster.
HPGL is an example of a vector format, TIFF is an example of a raster
format. EPS can support both.
Your choice among formats is largely dictated by your circumstances. For
web
use, GIF and JPEG are the main choices. If your final destination is
produced by a Postscript device, then EPS is probably the best choice. If
you're putting it on a Mac screen, then use PICT. For Silicon Graphics,
OpenGL is probably the best choice.
There, have I confused the issue enough?
Have fun,
Arlen
Chief Managing Director In Charge, Department of Redundancy Department
DNRC 224
Arlen -dot- P -dot- Walker -at- JCI -dot- Com
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In God we trust; all others must provide data.
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Opinions expressed are mine and mine alone.
If JCI had an opinion on this, they'd hire someone else to deliver it.
