[Live-demo] Saga Quickstart

Hamish hamish.webmail at gmail.com
Mon Sep 1 21:58:16 PDT 2014

Zoltan wrote:
> I've committed the changes of saga_quickstart.rst and some images to
> svn. revision 11959


this isn't a criticism, just a general reminder to people uploading
images about our ongoing struggle to free up every little bit of
disk space we can-

if running in a VM and the resolution has been stretched the image
comes out a bit dithered/out of focus, which has the tendency to make
the PNG images four times as big as they otherwise would have been.

If the screenshot has a high proportion of imagery check if a 85%
quality JPEG makes the filesize much smaller without compromising on
clarity. Images already fuzzed/dithered from a stretch will generally
look no worse as JPEGs (but try to avoid that happening in the first
place :).

For remaining PNGs run them through 'optipng -o5' or better crusher,
often this can save 30%, losslessly. If not using an alpha channel,
drop it back to just RGB from RGBA.

> I havn't change the last part with missing strm file.

Can SAGA deal with raw .hgt files? How about .hgt.zip without unzipping
them first? Those usually are less than 1.5mb per SRTM file so having
one of them on the disc would be fine I think. hgt should be more
relevant than an ancient Surfer grid anyway.

> I'll try to use some pointclouds or dtm from the available data.

I don't thing we ship any LAZ or LAS, but there is some lidar data
in ~/data/north_carolina/shape/ to play with (elev_lid*.shp). Also
in the NC raster dir there are a number of DEMs and satellite imagery
to drape over it.


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