Gerber OMEGA CP Reference Manual page 292

278 Chapter 27:
Importing files into Composer
Tip: GSP offers a program, MacImprint™, which drives the GERBER EDGE, GERBER EDGE 2,
and GSP plotters directly from Adobe Illustrator on a Macintosh without file conversion. See
the http://www.gspinc.com for more information on MacImprint.
Understanding PLT Files and raster files
The purpose of importing raster (bitmap, TIF, etc.) files into Composer is so that you can create
a PLT file to print. The PLT file is not, by definition, a raster file. But if you imported a raster file
into Composer, it uses that file to print.
When importing an image file you have the option to embed images or to maintain the image as
a linked file. The default setting is to link the file.
When importing a raster file, OMEGA creates a "thumbnail" bitmap image that is stored within
the structure of the PLT file. The thumbnail bitmap image influences the screen display of the
imported image in OMEGA but does not affect the printed output. You can set the resolution of
the thumbnail image in the Image Fill dialog box. The higher the resolution the more
realistically the image displays on the screen, but the larger the file size.
When importing a linked image, OMEGA creates a bitmap with the same file name as the
imported file. You must maintain the bitmap along with the PLT file in order to be able to print
the file. You can affect the output quality by changing the resolution of the imported bitmap.
Changing the resolution affects the associated BMP file, which, in turn, affects the printed PLT
file.
Embedding image files when importing stores the image within the PLT file. You do not need
to maintain the original image file.
Raster files and resolution
Follow these guidelines when assigning raster (bitmap) resolution:
♦ An associated BMP (or TIF) file with a higher resolution produces a more detailed
printed image but a larger file size.
♦ An associated BMP (or TIF) file with a lower resolution produces a less detailed
printed image but a smaller file size.
Note: The larger the file size, the more problematic its storage becomes, and the longer it takes
to process.
♦ For most purposes, a raster (BMP or TIF) file resolution of 100 to 300 dpi produces
good printed results.
♦ Size the image to the desired output size in Composer or GSPPlot before outputting it
to the printer.
♦ The intended viewing distance of the finished product is an important consideration
when deciding what resolution to use. Generally, doubling the viewing distance
allows you to halve the resolution. (A 150-dpi image viewed from 10 feet will appear
to have the same resolution as a 300-dpi image viewed from 5 feet.)