Harald, I use ImageMagick/GraphicsMagick to resample HUGE high resolution tiff images to something more manageable to work with. Using a script, I converted hundreds of images to lower resolution copies. Then it was simply a question of pointing ConTeXt to use the appropriate directory to find the right figures.
The basic comand is convert -resample 300x300 (or 100x100) and you can play with "-quality 75%" This can be done once and is much better than getting ConTeXt to convert every time on the fly. Alan On Mon, 9 Mar 2015 22:12:24 +0100 Harald Koenig <koe...@tat.physik.uni-tuebingen.de> wrote: > Hi, > > so here's my very generic question #1 for my India book: > > is it possible that context (lua?) will "shrink" all \externalfigure > jpegs automatically to some specified dpi resolution and quality > (e.g. 300 dpi with 95% jpeg 'quality' for print and > 100 dpi and 75% for screen quality) ? > > since I'm only using Linux, using Acrobat unfortueately is not an > option (thanks, Adobe:-( > > > that book will be ~100 A4 pages with ~50% and 50% pictures, > trying to have 2 pictures per page with text flowing around. > > the pictures are JPG photos with quite high resolution, upto 24 > Mpixel. so those picutres are HUGE and horrible overkill for a final > print on A4 with typical images withs around 0.5\textwith. > > > I know about ghostscript being able to convert/shrink PDFs, > but first the "original" PDF with full size JPGs with be really huge, > and ghostscript takes ages to shrink them. so that's not real fun > doing this too often... > > > right now I write the real typeset size of all images to the log file > and use some external script to calculate the current resolution > and then create a new set of images which e.g. 300 dpi. > > but that's still an ugly hack still has some issues with EXIF data, > rotation, clipping, ... and right now leads to strage problems (see > mext mail;) > > > > any hints to read the original large JPGs, but only write "print > quality" 300dpi images, or low quaity 75dpi images for speed (and > saving net bandwidth when mailing PDFs to co-workers of the group)? > > > thanks, > > Harald ___________________________________________________________________________________ If your question is of interest to others as well, please add an entry to the Wiki! maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context webpage : http://www.pragma-ade.nl / http://tex.aanhet.net archive : http://foundry.supelec.fr/projects/contextrev/ wiki : http://contextgarden.net ___________________________________________________________________________________
