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Compression panel
The Compression panel contains options for minimizing the size of a PDF file. For best
results in a service provider workflow, compression should be limited so that it doesn’t
degrade the output quality of the file. For ease of training, this panel is now very similar to
the same Compression panel in Adobe Illustrator CS and Acrobat Distiller 6.
Options in this panel give you control over how images and other elements in the InDesign
document are compressed. For each type of image, you can choose between downsampling
(which uses the average of the color values in a sample area) and subsampling (which uses
the color value of the pixel in the center of a sample area). Bicubic downsampling is the
slowest but most precise method, resulting in the smoothest tonal gradations.
In a print service provider workflow, output quality is the priority. If compression is applied,
downsampling will be more desirable than subsampling, and lossless compression will
provide higher quality than lossy compression. Remember that you or your customer can
simplify compression decisions just by choosing the Press PDF preset, which already uses
compression settings appropriate for a print service provider workflow.
