Printing

DS9 provides strong Postscript printing support. This is not a screen capture method, but a full level 1/2/3 postscript driver. The postscript images generated are detailed and accurate as possible, given the resolution of the data, and the printing resolution.

Postscript Level

Level 1-- The postscript generated consist of a color lookup table and image data, encoded in ASCIIHEX. All line graphics and text are postscript elements.

Level 2-- The postscript generated consist of a color lookup table and image data, compressed with RLE, and encoded in ASCIIHEX85. All line graphics and text are postscript elements.

Level 3-- The postscript generated consist of a color lookup table and image data, compressed with GZIP. All line graphics and text are postscript elements.

Postscript Color Model

DS9 supports three color models for level 2/3 postscript. All three color models generate approximately the same size files.

RGB
CMYK
Grayscale

Resolution

Unlike graphic elements, image data must be sampled when encoded into postscript. The specified resolution parameter is in "pixels per inch" and is independent of the current screen resolution. A value of 96 maps to the current screen resolution. Any value over 96 will over sample the image, while any value under 96 will under sample. For high resolution printers and posters, the higher resolution sampling, the better. However, keep in mind the size of the postscript file grows with the square of the increase in resolution.