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visualizing DEM data, LDEM 64.IMG in particular
JohnVV
post Jun 14 2010, 12:58 AM
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i received a mail , and feel that a forum discussion bests fits it .
i like open discussions better than mails for general discussions on topics ( more that one set of eyes)

the senders name removed ( if he wants to he can add to this thread - but that is his choice, not mine to make )
QUOTE
Hi John

I have followed your contributions on Unmannedspaceflight for some time now and always amazed as to what you are acheiveing 'visually' with the LDEM data and Blender in particular.

As purely an amatuer, and contributer more to LPOD discussions rather than to this forum (sometimes out of my league), I'm asking is it ever possible to take, say, the LDEM 64.IMG data file, which I have, and view the nemerical data details within?

I normally use the LDEM 64 data with the wonderful LTVT software by Jim Mosher and Henrik Bondo to produce lunar surface views, however, I feel limited (due to my in-experierence) in that I can't actually 'see' the data in the LDEM 64 file that I'm working in.

My eventual goal, for sometime now, is to take the above data in the LDEM 64, and inverse the nemerical values so as to make high points lower, and low points higher (e.g. concave craters eventually become convexed, mountains become valleys etc.,).

I'm not sure if there is any scientific value to all of the above conversions, however, I'd like to do the above thouigh my limited experience.


1) I'm asking is it ever possible to take, say, the LDEM 64.IMG data file, which I have, and view the nemerical data details within?
for going strait from the img format i import it into ISIS 3 ( but this can be very big ) a very min. install the program only to impotr pds img into .cub aprox 700 meg
full for cassini 25+ gigs
" and view the nemerical data details within"
this i am not sure of ? a image like this one in
http://www.unmannedspaceflight.com/index.p...mp;#entry150763
that is a 24 bit rgb convert
for a 16 bit gray as the "http://imbrium.mit.edu/DATA/LOLA_GDR/" is
i use Nip2 mostly once the img is in a usable format
image magick can also convert it but that is a bit " fun" to do (as a .gray image)
gdal can but i like isis
and do this say for the small LDEM_4.IMG
( from past exp it is a bin not ascii .img )
isis
import as raw for the small 4 map
raw2isis
720x 1440 and int 16 singed format
the image is in singed format
-- good for science but NOT for image viewers
this is what happens if you do not off set it
[attachment=21894:Screenshot.png]
well there is a post someplace on this forum about the LDEM images
offset and you get a good photo
[attachment=21895:Screenshot_1.png]

2 ) and inverse the nemerical values so as to make high points lower, and low points higher (e.g. concave craters eventually become convexed, mountains become valleys etc.,).

to invert is easy Nip2 can invert it
[attachment=21896:Screenshot_2.png]

---------------------
LTVT
http://the-moon.wikispaces.com/LTVT

i do not use MS windows and NEVER intend on owning win 7
System Requirements

* LTVT works only on Windows-compatible PC's
* It displays best using the "Windows Classic" desktop theme (simple window borders)

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