4.15. Use coolthumbs

coolthumbs is a small, fine script that will create antialiased thumbnails for your PDF document (those icons that look like miniature copies of your pages, in the left column of Acrobat Reader, besides the bookmarks tab). Whithout it, the thumbnails will look “high contrast” or “edgy”. Using coolthumbs will produce hight quality thumbnails, with the help of Ghostscript and The GIMP (which, of course, you must also have installed, if you decide to use it). You can get coolthumbs from the Linux LaTeX-PDF HOW-TO (I would love to include it here, but unfortunately its copyright notice does not allow it explicitly).

Install coolthumbs in, say, /usr/local/bin. Then enter its location in lyxtox and set the use_coolthumbs parameter to 1:

# Shall we use the coolthumbs script to create the PDF thumbnails?
# You can get coolthumbs from
# http://www.ringlord.com/publications/latex-pdf-howto/
# Note that you will also need to have GIMP installed
# and that you will have to edit some lines in coolthumbs too.
use_coolthumbs="1"

These are the values I had to change in my copy of coolthumbs:

• The location of The GIMP:

  # Program locations GIMP="/usr/bin/gimp" My GIMP scripts directory: # GIMPSCRIPTS: Your GIMP scripts directory. the file named by # SCALEALL will be CREATED there and then DELETED again: GIMPSCRIPTS=${HOME}/.gimp-1.2/scripts

• Width and height of the thumbnails:

  THUMBNAIL_W=74 THUMBNAIL_H=105

• Some explanation on the choice of those values is due here: the ISO/DIN paper sizes (in mm) for the various DIN paper sizes are shown in Table 4-1 (taken from Paper size).

  Table 4-1. ISO/DIN paper sizes

  	A	B	C
  0	841x1189	1000x1414	917x1297
  1	594x841	707x1000	648x917
  2	420x594	500x707	458x648
  3	297x420	353x500	324x458
  4	210x297	250x353	229x324
  5	148x210	176x250	162x229
  6	105x148	125x176	114x162
  7	74x105	88x125	81x114
  8	52x74	62x88	57x81
  9	37x52	44x62	40x57
  10	26x37	31x44	28x40

  From Table 4-1 we see that if, as the author of coolthumb says, the values of 82/106 are "pretty much dead-on" for US Letter paper, then the values 74/105 must be just as "dead on" for DIN paper (we try to match one paper side as good as possible - and in this case we see that 106-105 is pretty much as good as can be). More precisely, it's dead-on for for DIN A7 paper, but DIN papers have the same aspect ratio throughout the whole paper range (see Figure 4-2), so the ratio 74/105 for DIN A7 is the same as the ratio 210/297 for DIN A4 (which is mostly used outside the USA) and also the same as every other DIN paper.

  Figure 4-2. ISO-DIN paper sizes.

  

  ISO-DIN paper sizes.

• DPI (dots-per-inch) value for the thumbnails:

  SNAPSHOT_DPI=133

• This is the DPI value of my monitor, as taken from the output of the graphic card driver in /var/log/XFree86.0.log, where it says:

  DPI set to (133, 133)

  Of course, YMMV (=Your Monitor May Vary ;-)).

• I use thumbpdf version 3.2, so I set

  THUMBPDF_V2=0