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<DIV><FONT size=2>It'a a dynamic rotation, the convergence of whatever
coordinate system you are woirking in, at the center of your area ot
interest.</FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2>Steve</FONT></DIV>
<BLOCKQUOTE dir=ltr
style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=ed@topozone.com href="mailto:ed@topozone.com">Ed McNierney</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A title=gdal-dev@remotesensing.org
href="mailto:gdal-dev@remotesensing.org">gdal-dev@remotesensing.org</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Tuesday, August 19, 2003 2:47
PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> RE: [Gdal-dev] Warp /
rotation</DIV>
<DIV><BR></DIV>
<DIV><SPAN class=906544320-19082003><FONT face=Arial color=#0000ff size=2>I
think you missed the point - a rectangle rotated is no longer a
rectangle. It's a four-sided polygon, a quadrilateral, etc. - what's
important is that you are requesting an area that, expressed in the source
coordinate system, is not rectangular. If the Y coordinates of the lower
left and lower right corners are different, it's not a
rectangle.</FONT></SPAN></DIV>
<DIV><SPAN class=906544320-19082003><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=906544320-19082003><FONT face=Arial color=#0000ff size=2>Can
you provide a rigorous definition of your rotation? "About 2 degrees CW"
isn't precise enough. If you can describe it mathematically, we can help
you implement it!</FONT></SPAN></DIV>
<DIV><SPAN class=906544320-19082003><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=906544320-19082003> <FONT face=Arial
color=#0000ff size=2>- Ed</FONT></SPAN></DIV>
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<DIV class=OutlookMessageHeader dir=ltr align=left><FONT face=Tahoma
size=2>-----Original Message-----<BR><B>From:</B> Geographic Wizard
[mailto:geowiz@shaw.ca]<BR><B>Sent:</B> Tuesday, August 19, 2003 4:37
PM<BR><B>To:</B> gdal-dev@remotesensing.org<BR><B>Subject:</B> Re:
[Gdal-dev] Warp / rotation<BR><BR></FONT></DIV>
<DIV><FONT size=2>The coordinates in the sample are UTMs and the rectangle
is a rectangle, just rotated. I guess what I am looking for is a quick and
easy way to pull the subimage with a rotation applied, maybe.</FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2>These are UTM's, but they really could be any kind of
coordinate.</FONT></DIV>
<BLOCKQUOTE dir=ltr
style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=ed@topozone.com href="mailto:ed@topozone.com">Ed McNierney</A>
</DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A
title=gdal-dev@remotesensing.org
href="mailto:gdal-dev@remotesensing.org">gdal-dev@remotesensing.org</A>
</DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Tuesday, August 19, 2003 11:10
AM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> RE: [Gdal-dev] Warp /
rotation</DIV>
<DIV><BR></DIV>
<DIV><SPAN class=591090817-19082003><FONT face=Arial color=#0000ff
size=2>Dear Wizard -</FONT></SPAN></DIV>
<DIV><SPAN class=591090817-19082003><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=591090817-19082003><FONT face=Arial color=#0000ff
size=2>The problem is that your "rectangle" isn't a rectangle! You
seem to be trying to reproject your image - can you describe the input and
output projections you're using? Those numbers make it look like
your input data might be in UTM (but it could certainly be something
else), but what is your desired output projection?</FONT></SPAN></DIV>
<DIV><SPAN class=591090817-19082003><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=591090817-19082003> <FONT face=Arial
color=#0000ff size=2>- Ed</FONT></SPAN></DIV>
<DIV><SPAN class=591090817-19082003>
<P><FONT size=2>Ed McNierney<BR>President and Chief
Mapmaker<BR>TopoZone.com / Maps a la carte, Inc.<BR>73 Princeton Street,
Suite 305<BR>North Chelmsford, MA 01863<BR>ed@topozone.com<BR>(978)
251-4242 </FONT></P></SPAN></DIV>
<BLOCKQUOTE dir=ltr style="MARGIN-RIGHT: 0px">
<DIV class=OutlookMessageHeader dir=ltr align=left><FONT face=Tahoma
size=2>-----Original Message-----<BR><B>From:</B> Geographic Wizard
[mailto:geowiz@shaw.ca]<BR><B>Sent:</B> Tuesday, August 19, 2003 12:58
PM<BR><B>To:</B> gdal-dev@remotesensing.org<BR><B>Subject:</B>
[Gdal-dev] Warp / rotation<BR><BR></FONT></DIV>
<DIV>
<DIV><FONT size=2>
<DIV><FONT size=2>Hi, everybody</FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2>New to GDAL as well as using georeferenced raster
images. I am trying to figure out how to do the following, and any help
/ insight would be greatly appreciated. I have put some numbers together
as an example :</FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2>I have an image (tif/jpg/png) 5000 x 5000 that is
georef with a world file</FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2>2</FONT></DIV>
<DIV><FONT size=2>0</FONT></DIV>
<DIV><FONT size=2>0</FONT></DIV>
<DIV><FONT size=2>-2</FONT></DIV>
<DIV><FONT size=2>667500</FONT></DIV>
<DIV><FONT size=2>5864000</FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2>I would like to pull a sub image of this that is bound
by a rectangle</FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2> 669273---------------------------
670898</FONT></DIV>
<DIV><FONT size=2>5862482---------------------------
5862538</FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2> 669330---------------------------
670956</FONT></DIV>
<DIV><FONT size=2>5860859---------------------------5860910</FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2>I would like line # 1 of the sub-image to be along the
top boundary of the rectangle, therefore it needs to be rotated by about
2 degrees cw.</FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2>Any help would be appreciated.</FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2>Thanks,</FONT></DIV>
<DIV><FONT
size=2>Steve</FONT></DIV></FONT></DIV></DIV></BLOCKQUOTE></BLOCKQUOTE></BLOCKQUOTE></BLOCKQUOTE></BODY></HTML>