--- Begin Forwarded Message ---
Date: Thu, 23 Sep 1999 09:08:24 -0500
From: [log in to unmask]
Subject: Re: airphoto mosaic <fwd>
Sender: [log in to unmask]
Once the photos have been corrected and geo-referenced (I suggest this be done
by a planimetric firm) the resulting geo-referenced Tiffs can be automatically
assembled into a mosaic using MrSID Compress (www.lizardtech.com.) with the
added benefit of 30:1 - 50:1 compression with very little loss. I can open a 200
MB image that has been converted to .sid format in about 1 second.
MrSID stands for Multi-resolution Seamless Image Database and is the standard
adopted by the United States Geologic Survey for compressing and seaming maps
and digital orthos. The United States Library of Congress has also adopted this
standard. Adobe has selected MrSID as the Portable Image Format for PDF. The
viewer is free and is supported by Intergraph and ESRI in GIS environments.
Bill Mason
McLeodUSA, Inc
[log in to unmask]
(Embedded
image moved Johnnie Sutherland <[log in to unmask]>
to file: 09/22/99 03:06 PM
pic03244.pcx)
Please respond to Umberto Fracassi <[log in to unmask]>
To: [log in to unmask]
cc: (bcc: William G. Mason/MCLEOD)
Subject: airphoto mosaic <fwd>
--- Begin Forwarded Message ---
Date: Wed, 22 Sep 1999 18:43:46 +0200 (CEST)
From: Umberto Fracassi <[log in to unmask]>
Subject: airphoto mosaic
Sender: Umberto Fracassi <[log in to unmask]>
Hi all,
first of all, apologies for cross postings - and for the rather basic
question..!
I have a set of about 50 scanned aerial images, that I need to re-compose
in a mosaic. Of course, the target is to have them georeferenced, somehow
a little orthocorrected (if possible..)..
Then, I have a two-fold question.
The first is:
- graphical. I scanned the photos @ 300 dpi, acquiring the whole image.
Although for georeferencing I'll use the fiducials (which lie within the
main photo boundary), do I need to retain the black border at all (with
the flight and frame number)..? I know this sounds a bit stupid..
and the second is:
- a bit more technical. To obtain the mosaic, I have assumed that, once I
georeference every image, then any mosaicking routine 'should' recognise
the location of each photo and place each where it should - also
compensating for the slight difference in scale among photos and
flightlines..? - Is this really going to be this straightforward (..) or
am I missing some crucial point..?
Sorry for the rather basic issue, it's the first time I go digital in
mosaicking airphotos..
Thanks in advance for any help!
Umberto
Umberto Fracassi
---------------------------------------------------------------
Dip.to di Scienze della Terra
Universita' di Firenze
Via I. Nardi, 2
50132 Firenze
Italy
Tel: +39-055-243486
Fax: +39-055-241595
Email: [log in to unmask]
WWW: http://ewse.ceo.org/construct/build.pl/665027
---------------------------------------------------------------
*********************
"This is what you should do: Love the earth and the sun and the animals,
despise riches, give alms to everyone that asks, stand up for the stupid
and crazy, devote your income and labor to others, hate tyrants, argue not
concerning god, have patience and indulgence toward people, take off your
hat to nothing known or unknown, or to anyone or number of people
...reexamine all you have been told at school or church, or in any book,
dismiss what insults your soul, and your very flesh shall be a great
poem."
Walt Whitman
*********************
--- End Forwarded Message ---
--- End Forwarded Message ---
|
