Graphics Programs Reference
In-Depth Information
If you zoom way into this bitmap copy, you'll see color
pixels that the Bitmap Tracer will notice but really
shouldn't notice. Some color-dithered areas in the land
masses and in the ocean parts should be moved in color
value to the rest of the desired colors in the graphic.
This is a job for one of the Live Effects that ships with
Xara Xtreme. With the bitmap copy
selected, choose the Live Effect
Tool—the icon with the plug on it
(live effects are plug-ins)—from the
On the Infobar, click New to access
the drop-down list of available
filters. Choose Color Filter | Poster.
Drag the Grades slider down from
its default of 256 maximum possible
colors to 5. This action moves
certain values in the globe image to
more frequent ones, makes the edges
well defined, and in general makes
the image better suited for a very
clean auto-trace. Click the Close
button at the upper-right corner of
the slider box.
By default (which you can change in Utilities | Options),
Live Effects bitmaps are rendered to screen resolution
(96ppi), but you want to maintain the 280ppi resolution
you specified for the copy in step 6. Click in the field to
the right of the Edit button on the Infobar (it should say
Automatic). Type 280 in the field and then press ENTER .
Because this is a Live Effects object, it doesn't count
as a new bitmap that Bitmap Tracer can trace, so you
need to make a copy now and, in the process, reduce the
unique number of colors still farther. Press CTRL - SHIFT - C ,
and then in the Create Bitmap Options box on the
Palette Options tab, choose 256 Colors from the Color
Depth drop-down list, choose the Optimized Palette,
and set Dithering to None. Then on the Bitmap Size
tab, make the resolution the same as the current image
(280 dpi) and click Create. You can delete the original
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