[Live-demo] What options to use with pngcrush?

[Hamish]

Cameron wrote:
> I notice that when I try running pngcrush, I get hundreds of
> options. Can you please suggest which options we should
> recommend osgeo-live users on this page:
> http://wiki.osgeo.org/wiki/Live_GIS_Add_Project

optipng is already listed there with an example (-o5). Use it
instead.

fwiw I usually used 'pngcrush -brute infile outfile', but these
days I mostly use optipng as it seems (anecdotally) slightly
better. There are many roads to Rome, so take your pick.


n.b. (at every opportunity :) it is not worth checking in image
replacements which are only 1-2% smaller, it just eats up space
in the SVN database (due to retained file history, files are
never removed even when replaced, lots of iterations of binary
files just causes backend database bloat). Almost all pngs in the
svn older than a few months have already been crushed. You can
get them smaller by making them a palette image or reducing the
bit depth, at the cost of perhaps-noticeable (perhaps-not)
quality. Stuff with a lot of shading or satellite imagery should
perhaps be .jpg, stuff with many spans of solid color should be
.png.


cheers,
Hamish