WCS and 32-bit FLOAT GeoTIFFS

[John Cartwright]

Thanks for your reply Frank.  I don't think that the georeferencing is
the problem here.  Originally I had the following in the mapfile:

OUTPUTFORMAT
      NAME GEOTIFF_RGB
      DRIVER "GDAL/GTiff"
      IMAGEMODE RGB
      FORMATOPTION "INTERLEAVE=BAND"
END

Same WCS request and datafile produced a TIFF described as:

Driver: GTiff/GeoTIFF
Size is 90, 45
Coordinate System is:
GEOGCS["WGS 84",
    DATUM["WGS_1984",
        SPHEROID["WGS 84",6378137,298.2572235629972,
            AUTHORITY["EPSG","7030"]],
        AUTHORITY["EPSG","6326"]],
    PRIMEM["Greenwich",0],
    UNIT["degree",0.0174532925199433],
    AUTHORITY["EPSG","4326"]]
Origin = (-105.016854,40.517045)
Pixel Size = (0.03370787,-0.03409091)
Metadata:
  AREA_OR_POINT=Area
Corner Coordinates:
Upper Left  (-105.0168539,  40.5170455) (105d 1'0.67"W, 40d31'1.36"N)
Lower Left  (-105.0168539,  38.9829545) (105d 1'0.67"W, 38d58'58.64"N)
Upper Right (-101.9831461,  40.5170455) (101d58'59.33"W, 40d31'1.36"N)
Lower Right (-101.9831461,  38.9829545) (101d58'59.33"W, 38d58'58.64"N)
Center      (-103.5000000,  39.7500000) (103d30'0.00"W, 39d45'0.00"N)
Band 1 Block=90x45 Type=Byte, ColorInterp=Red
Band 2 Block=90x45 Type=Byte, ColorInterp=Green
Band 3 Block=90x45 Type=Byte, ColorInterp=Blue


Comparing this the the TIFF created w/ the FLOAT32 imagemode, the georef
looks the same, but (naturally) the data type is different:

Driver: GTiff/GeoTIFF
Size is 90, 45
Coordinate System is:
GEOGCS["WGS 84",
    DATUM["WGS_1984",
        SPHEROID["WGS 84",6378137,298.2572235629972,
            AUTHORITY["EPSG","7030"]],
        AUTHORITY["EPSG","6326"]],
    PRIMEM["Greenwich",0],
    UNIT["degree",0.0174532925199433],
    AUTHORITY["EPSG","4326"]]
Origin = (-105.016854,40.517045)
Pixel Size = (0.03370787,-0.03409091)
Metadata:
  AREA_OR_POINT=Area
Corner Coordinates:
Upper Left  (-105.0168539,  40.5170455) (105d 1'0.67"W, 40d31'1.36"N)
Lower Left  (-105.0168539,  38.9829545) (105d 1'0.67"W, 38d58'58.64"N)
Upper Right (-101.9831461,  40.5170455) (101d58'59.33"W, 40d31'1.36"N)
Lower Right (-101.9831461,  38.9829545) (101d58'59.33"W, 38d58'58.64"N)
Center      (-103.5000000,  39.7500000) (103d30'0.00"W, 39d45'0.00"N)
Band 1 Block=90x22 Type=Float32, ColorInterp=Gray


I can convert the data being served by Mapserver to a raw binary file of
16-bit signed integers, but it's not clear that Mapserver (via GDAL)
supports this format of data.  Should the EHdr driver work for this?

Thanks again for your help!

--john
  
----- Original Message -----
From: Frank Warmerdam <warmerdam at pobox.com>
Date: Friday, October 27, 2006 6:11 pm
Subject: Re: [UMN_MAPSERVER-USERS] WCS and 32-bit FLOAT GeoTIFFS

> John Cartwright wrote:
> > Hello All,
> > 
> > I've got a 32-bit float geotiff that I'm serving via WCS.  
> Strangely, 
> > GetCoverage requests are returning geotiffs comprised entirely of 
> no 
> > data values.
> > 
> > Here's my OUTPUTFORMAT section in the mapfile:
> > OUTPUTFORMAT
> >  NAME GTiff
> >  DRIVER "GDAL/GTiff"
> >  MIMETYPE "image/tiff"
> >  IMAGEMODE FLOAT32
> >  EXTENSION "tif"
> > END
> > 
> > and I'm specifying "format=gtiff" in the request.
> > 
> > Can someone help me with what I'm doing wrong?
> 
> John,
> 
> My guess would be that this is a problem of location.  That there 
> mightbe some mixup in MapServer's assumptions about where the input 
> files are
> such that they don't get drawn in response to the requests that 
> come in.
> This issue could be the input files themselves, the layer 
> definition or
> details of the WCS request coming in.  I don't see any problem with 
> theoutput format declaration you have used.
> 
> Best regards,
> -- 
> ---------------------------------------+----------------------------
> ----------
> I set the clouds in motion - turn up   | Frank Warmerdam, 
> warmerdam at pobox.comlight and sound - activate the windows | 
> http://pobox.com/~warmerdamand watch the world go round - Rush    | 
> President OSGeo, http://osgeo.org
> 
>