adding graphics to files

[Fred Ridder]

Deirdre Reagan wrote:
> Anyhow, when I add jpgs to my Framemaker file (FM 8.0, Windows XP),
> Framemaker slows way down when I scroll over the page with the jpg.
> 
> The jpgs are 300 dpi, which they need to be for good print resolution
> (they are black and white drawings).
> 
> I import the file to an anchored frame, then resize the graphic to 80
> percent because it is usually too large for the anchored frame.
> 
> I really don't know anything about graphics, so anything advice would
> be most appreciated.
 
To cover only a couple of the most basic issues:
 
First and foremost, JPEG is *not* an appropriate file format for line art
or anything containing text. JPEG was specifically designed for 
*photographic* images, which tend to conceal many of the format's
shortcomings due to the continuous-tone nature of photographs. 
JPEG's area-based image compression algorithm inherently produces 
artifacts near abroupt color transitions, which is clearly seen as a 
kind of gray smudginess alongside lines in drawings or as a kind of 
cloud surrounding text. For line art you should be using a lossless file
format like EPS, WMF (or EMF), or PNG (or GIF or TIFF or even BMP).
The one file format you should *not* use is JPEG.
 
Second, if you need to scale your graphics, you should use a vector
file format (EPS, WMF, EMF) rather than a raster file format (any of 
the others mentioned). Vector images contain mathematical descriptions
of the geometric and text objects in the drawing, which means that 
they can be rescaled over a wide range of sizes with no loss in quality.
Raster graphics contain a pixel-by-pixel rendering of the image, and 
to rescale them you either have to change the pixel pitch or you have
to resample them to throw away pixels or make up new pixels that 
don't exist. 
 
Third, if you do have raster images (screen shots, for example), the 
best way to change their reproduced size in FrameMaker is not 
to use the scaling command, but rather to change the dpi setting. 
Doubling the dpi will reduce the dimensions to 50%; halving the 
dpi will double the reproduced size of the image. If this approach 
is not acceptable for some reason, the other alternative is to use
a tool like PaintShop Pro or Photoshop to resample the image, but
this *always* causes a loss in quality.
 
I'll leave any other issues to others to address.
 
-Fred Ridder