extent is invalid for geotiff

[Ed McNierney]

John -

You may have two separate problems, one of which may be a non-problem.

1. If the image is "smaller than [you] would expect, and offset
vertically", could that simply be because the EXTENT is slightly larger
than the geographic extent of the image, and offset vertically?  Try
adjusting the numbers in the EXTENT line.  If you view the TIFF image in
an image viewer, does the imagery fill the frame, or is there blank
space around it?

2. In your HTML template, you have somewhere an <IMG> tag to display the
map, which looks something like <IMG SRC=[img]....>.  Is there a HEIGHT
and WIDTH field in that tag?  Are they 300 and 400, respectively?  If
those values don't match the SIZE in your map file, you're asking to
display the image at a different size than it was produced, which will
give odd results.

        - Ed

Ed McNierney
President and Chief Mapmaker
TopoZone.com / Maps a la carte, Inc.
73 Princeton Street, Suite 305
North Chelmsford, MA  01863
ed at topozone.com
(978) 251-4242 

-----Original Message-----
From: John Bonk [mailto:bonk at eosdata.gsfc.nasa.gov] 
Sent: Thursday, February 10, 2005 3:55 PM
To: Ed McNierney; John Bonk; MAPSERVER-USERS at LISTS.UMN.EDU
Subject: RE: [UMN_MAPSERVER-USERS] extent is invalid for geotiff

Ed,

Thank you again for responding to my question.

I'm still having problems understanding extent.

When I serve up my geotiff with your extent using

MAP
   IMAGETYPE PNG
   EXTENT -13053641.3 3358256.867 -932579.471 5752577.812

   SIZE 400 300
   SHAPEPATH "data"

   LAYER # MODIS raster layer begins here
     NAME modis
     DATA RGB_mosaic_250m.tif
     STATUS DEFAULT
     TYPE RASTER
   END # MODIS raster layer ends here

END # end of map file

I end up with an image that is smaller than I would expect, and offset
vertically.

If I add an html template to the above and serve the geotiff in the
browse mode, the image in the geotiff occupies a very small area in the
png that is produced.  The geotiff image is left justified and centered
vertically in the png.

Can anyone explain why this is?  How can I get the geotiff image to fill
the entire png?

John



At 09:41 2005-02-08 -0500, Ed McNierney wrote:
>John -
>
>No, there isn't any preferred method.  A GeoTIFF will hold projection, 
>datum, and bounding box information in a way that can be read by 
>MapServer.  As long as the GeoTIFF is created properly (i.e. you can't 
>leave out the projection) the coordinate formats used don't matter.
>
>         - Ed
>
>Ed McNierney
>President and Chief Mapmaker
>TopoZone.com / Maps a la carte, Inc.
>73 Princeton Street, Suite 305
>North Chelmsford, MA  01863
>ed at topozone.com
>(978) 251-4242
>
>-----Original Message-----
>From: UMN MapServer Users List [mailto:MAPSERVER-USERS at LISTS.UMN.EDU] 
>On Behalf Of John Bonk
>Sent: Monday, February 07, 2005 11:39 AM
>To: MAPSERVER-USERS at LISTS.UMN.EDU
>Subject: Re: [UMN_MAPSERVER-USERS] extent is invalid for geotiff
>
>Ed,
>
>Thank you, that worked.  I seems obvious now when I look back at the 
>documentation.
>
>Perhaps someone can answer another question.  In creating geotiffs, is 
>there a preferred way of specify coordinates (degrees, UTM, etc)  so 
>that the image will work well with MapServer?
>
>Thanks again for the response,
>John
>At 23:10 2005-02-04 -0500, Ed McNierney wrote:
> >John -
> >
> >If that's the only data layer in your map, ignore PROJECTION 
> >completely, at least for now.
> >
> >Have you tried an EXTENT of:
> >
> >EXTENT -13053641.3 3358256.867 -932579.471 5752577.812
> >
> >         - Ed
> >
> >Ed McNierney
> >TopoZone.com
> >
> >-----Original Message-----
> >From: UMN MapServer Users List [mailto:MAPSERVER-USERS at LISTS.UMN.EDU]
> >On Behalf Of John Bonk
> >Sent: Friday, February 04, 2005 5:08 PM
> >To: MAPSERVER-USERS at LISTS.UMN.EDU
> >Subject: [UMN_MAPSERVER-USERS] extent is invalid for geotiff
> >
> >I am very new at this.  I am having problems serving a geotiff image 
> >with the following attributes:
> >
> >Projection Method: CT_Equirectangular
> >     ProjCenterLatGeoKey: 0.000000 (  0d 0' 0.00"N)
> >     ProjCenterLongGeoKey: 0.000000 (  0d 0' 0.00"E)
> >     ProjFalseEastingGeoKey: 0.000000 m
> >     ProjFalseNorthingGeoKey: 0.000000 m
> >
> >Corner Coordinates:
> >Upper Left    (-13053641.300,5752577.812)
> >Lower Left    (-13053641.300,3358256.867)
> >Upper Right   (-9325729.471,5752577.812)
> >Lower Right   (-9325729.471,3358256.867)
> >Center        (-11189685.386,4555417.340)
> >
> >I have tried all sorts of variation of these number in the EXTENT 
> >field
>
> >but  I have been getting an 'extent is invalid' message.
> >
> >Can anyone help me express the EXTENT and PROJECTION to read this
file?
> >
> >John
> >=======================================
> >

=======================================
John Bonk
SSAI/NASA GES DISC
Phone:(301) 614-5280
Fax:  (301) 614-5268
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