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were $ is a bash prompt, GS> a ghostscript one.

Creating a PDF from postscript {{{

gs -dNOPAUSE -sOutputFile=out1.pdf -sDEVICE=pdfwrite -dPDFSETTINGS=/screen -dBATCH file.ps

Other settings for -dPDFSETTINGS

• /prepress
• /screen
• /printer
• /default
• /ebook

}}}

Changing Page Sizes/ Offsets (eg. to crop to A5) {{{

$gs -dNOPAUSE -sOutputFile=out1.pdf -r300 -sDEVICE=pdfwrite -dFIXEDMEDIA=true -g2480x1754

• The -gWIDTHxHEIGHT is specified in pixels (ie. 300 per inch with the -r300).
• type exactly but replace x and y with the page offset in points:

GS> << /PageOffset [x y] >> setpagedevice
GS> (print.ps) run

• then press ctrl-D to exit GS.

Examples

• image at top of page, you want to shift it down, use y<0
• when gs crops a page, the new page is bottom-right aligned (hmmm, handy…)

This:

<< /PageOffset [0 -420.945 ] >> setpagedevice

is what you need if you have:

a4:

 +++++++
 | XXX |
 | XXX |
 |     |
 |     |
 +++++++

and you want:

 a5
 +++++++
 | XXX |
 | XXX |
 +++++++

the -g option

the numbers refer to pixels (2480 = 300dpi x 210mm / (25.4mm/inch) )

@300dpi,

• A5 landscape: -g2480x1754
• A5 portrait : -g1754x2480
• A4 landscape: -g2480x3508

}}}

Explaining {{{

GS> << /PageOffset [x y] >> setpagedevice
    -- ----------- ----- -- + this is a Level 2+ feature that alters
    |       |        |   |    the "page device dictionary"
    |       |        |   +--- this is "end of dictionary": puts it on stack
    |       |        +------- an array of two values assigned to the key
    |       |                 in the dictionary being defined.
    |       +---------------- the name for the key in the dictionary
    +------------------------ this is "start of dictionary"

Other options for page device: (* level 3 operator):

/PageSize               Takes array [w h]
/ImageBBox              Takes array [l b r t] or null. Anything outside 
                        this box won't be painted. Set to null for max.
                        Should always set to null after setting /PageSize
/Separations*           boolean
/SeparationColorNames   
/ImageShift*            Takes array [x y]. On front sides, x = left,
                        y = up. On back it would be reversed.
/PageOffset*            Seems to me to be the same.
/Margins                This is for device-dependant adjustments and
                        shouldn't be used for page positioning.
/ProcessColorModel      one of
                        DeviceGray, DeviceRGB, DeviceCMYK,
                        DeviceCMY, DeviceRGBK, DeviceN*
                        (ref. p.422)

}}}

Colour Separations {{{

There’s an “aurora” script for this written by Graham Freeman g-freeman@adfa.edu.au

$ cat aurora black 85.lpi myfile.ps >myfile_black_plate.ps

$ cat aurora cyan 85.lpi myfile.ps >myfile_cyan_plate.ps

can do for cmyk and red, blue and green. Only postscript level1 though.

}}}

Output one file per page {{{

-sOutputFile=ABC-%d.png
    produces 'ABC-1.png', ... , 'ABC-10.png', ...

-sOutputFile=ABC-%03d.pgm
    produces 'ABC-001.pgm', ... , 'ABC-010.pgm', ...

-sOutputFile=ABC_p%04d.tiff
    produces 'ABC_p0001.tiff', ... , 'ABC_p0510.tiff', ... , 'ABC_p5238.tiff'

}}}