-----Original Message-----
From: Michael Tang [mailto:[EMAIL PROTECTED]]
Sent: Tuesday, June 20, 2000 10:31 PM
To: [EMAIL PROTECTED]
Subject: MI Combining Two Rasterized Images and reproduce as 1 map
Dear All,
I have not attempted this exercise thus, I need to seek your expert advice.
I have a seismic survey area which covers two digital maps from two
different sources. Imagine the scenario whereby a rectangle area covers the
western edge of Map 1 and the other part covers the eastern edge of Map 2.
Question:
1. Can I register the two maps in two different tables (same geodetic
datum) and later combine them to make 1 master sheet?
Combining two images is possible in photo editing software, but it would be
much easier to just use two tables, each with the maps registered
independently.
2. If so, I guessed I can then import a .MIF file of the survey polygon
which spans both the maps which is now a master sheet.
If you already have a table with a polygon, it should already display on any
correctly registered tables.
3. What will the precision like? Does the precision a function of the
resolution of the raster image (as both are from difference scale and
different source).
The grossest scale will be the best you can get. In addition, you must be
very careful to register the maps very well, as using two rasters in the
same map seems to change the projection system slightly to try to
accommodate both registrants. I have not figured out a way around this,
other than displaying only one map at a time.
What kinds of maps do you have?
4. My argument is that since the geocoding/image registration is dependant
on the geographicals, thus I do not see any problem with it but at the
intersection point.
I has been my experience, that even when you register two rasters (i.e. topo
maps or orthophotos) with exactly the same points, they still sometimes
don't join exactly. The key word is **sometimes**, which is the frustrating
part. You can register two pictures, have them show up with a space
between, then zoom into the space, and it will disappear! Zoom back out, it
is still gone! Zoom in, it returns!???!
The best way around is to join the pictures in a photo image program, but
again, that can be more trouble than it is worth to join them and
re-register the new picture.
I'd be curious to find if anyone has had success with multiple images, or
overlaying types of images.
I am open to suggestions and comments.
Best regards
Michael Tang
Schlumberger Oilfield Services
Asia, Middle East & Australia
----------------------------------------------------------------------
To unsubscribe from this list, send e-mail to [EMAIL PROTECTED] and put
"unsubscribe MAPINFO-L" in the message body, or contact [EMAIL PROTECTED]
----------------------------------------------------------------------
To unsubscribe from this list, send e-mail to [EMAIL PROTECTED] and put
"unsubscribe MAPINFO-L" in the message body, or contact [EMAIL PROTECTED]
