What CGM Is

[Liz Babcock <Liz_Babcock -at- JDAM -dot- CHINALAKE -dot- NAVY -dot- MIL>]

Mail*Link(r) SMTP               What CGM Is

On 7-20 I asked on behalf of Cindy Elliott, who is not on the list,
>What is CGM? How well does it work? How easy is it to learn? What does it
cost? >Where's the best place to get it? And any other information on CGM that
you >think would help.

A big thank you from Cindy Elliott--and me--for the prompt, helpful responses
from Stuart Sipahigil, Sue Gallagher, Rikki Nyman, Steve Hollander, Debbie
Lemasters, Rex Ungericht, Bonni Graham, Roxanne L. Lewis, and Tommy Trussel.
All agreed that CGM is a graphics *format*, not a *program*. I'll include
representative quotes to summarize what all told me.

Debbie Lemasters said:
>CGM is one of many graphics file formats.  It stands for
>Computer Graphics Metafile.  Because it is a common
>format, it is understandable that a client would want the
>graphics done in that format.  Also, *.CGM files take up
>less room generally than some other kinds.  I think it's
>because these files are vector-based and in binary
format, but this part's unclear to me. Bitmaps, on the
>other hand, *.BMP, take up the most room.  That's
>because bitmaps store every pixel.

>For example. . . . .
  >CorelDraw! 4.0 can export art into 21 different graphics file
>formats.  *.CGM, *.BMP, .*EPS, and *.TIF   are among the 21.
  >Adobe Illustrator 4.02 can export art into 11 formats,
>including *.CGM, *.BMP, and *.TIF.
  >FrameMaker 4.0 can import 20 kinds of formats,
>including *.CGM, *.BMP, *.EPS, and *.TIF.
  >Word 6.0 can import 19 kinds of formats,
>including *.CGM, *.BMP, *.EPS, and *.TIF.

>I'm sure the client wants a format that can be exported easily
>from whatever art package they are using and imported easily
>into whatever text processing system they are using.

Steve Hollander observed helpfully that:
>Software like HiJaak would be able to convert other popular formats (e.g.
>TIF, EPS) to CGM.

Finally, Tommy Trussell had several helpful hints for Cindy:
> (snip) It is a very common and reliable export format for many PC
> graphics packages, however, including Corel Draw and MacDraw.

>The client may be insistent that you use a particular program because they
>want to be able to edit the files.  Depending upon how the program creates
>the file, this may or may not be possible.  (In general, the graphics
>should be "object oriented" rather than "raster," and they MUST stay that
>way when you export them.)

>To create graphics in CGM format, then you need only export them from
>whatever graphics program you are already using.  Several companies make file
>translation programs, but in general it's better to export directly from the
>original program if that feature is available.

>I would recommend exporting a few moderately complex graphics in the style
you >expect to use (be sure to include some text if you ever expect to use
it!), and >arrange to send the files to them for testing.  This will let you
test several >things, including:
   >o The file transfer (whether they get the files, and are they intact),
   >o The export function in the graphics program, and
   >o How much the client is willing to help you.

Many thanks, whirlers, and I think Cindy now considers her questions well
answered!

Liz Babcock
liz_babcock -at- jdam -dot- chinalake -dot- navy -dot- mil