Printing Posters on GWDG Printers

Via one of GWDG’s Linux Dialogservers

I was previously able to simple add the printer and type in my password when I wanted to print, but this does not work anymore for me. I wrote the GWDG Support and they gave me one way that worked:

1. Export your poster as an JPEG file. If you use Inkscape like me, you probably need to export it as PNG first and convert it to JPEG with imagemagick. When you export it to PNG, do not simply use save as, rather use export as png! There you can choose the size and everyting, make sure you use some physical length in mm, cm or inches, not pixels! You can convert with imagemagick in the command line:

   $ convert poster.png poster.jpg
   

2. Check print parameters for your JPEG, again with imagemagick:

   $ identify -verbose poster.jpg
   

   Important are the entries for Print size, Resolution, and Units. They have to be some physical units, that you can match to A0 or whatever size you want. If Units: PixelsPerInch, the Print size refers to Inches, If Units: PixelsPerCm or something, the Print size is in cm, etc. The Resolution tells you the dpi or dots per cm or whatever your unit is.

   • example:

     $ identify -verbose DQ_A3_400ppi_sRGB_dt.jpg
     Image: DQ_A3_400ppi_sRGB_dt.jpg
       Format: JPEG (Joint Photographic Experts Group JFIF format)
       Mime type: image/jpeg
       Class: DirectClass
       Geometry: 6614x4677+0+0
       Resolution: 400x400
       Print size: 16.535x11.6925
       Units: PixelsPerInch
       ...
     

   • example:

     $ identify -verbose poster.jpg
     Image: poster.jpg
       Format: JPEG (Joint Photographic Experts Group JFIF format)
       Mime type: image/jpeg
       Class: DirectClass
       Geometry: 9933x14043+0+0
       Resolution: 118x118
       Print size: 84.178x119.008
       Units: PixelsPerCentimeter
       ...
     

3. Copy file to an GWDG dialog server, e.g. gwdu60.gwdg.de. You need an GWDG account for that! You can copy via scp or rsync. E.g., I use:

   $ rsync -uvt poster.jpg ikuhlem@gwdu60.gwdg.de:
   

   And then login to the server:

   $ ssh ikuhlem@gwdu60.gwdg.de
   

4. Print from dialog server via command line. E.g. to print on the poster printer pcipls in the physics library:

   $ lpr -Ppcipls poster.jpg
   

Done!