[GRASS-user] Import/conversion problem
Adam Dershowitz, Ph.D., P.E.
adershowitz at exponent.com
Fri Feb 11 16:56:49 EST 2011
On Feb 11, 2011, at 12:14 PM, Stuart Edwards wrote:
> I'm not familiar with the Kyngesburye plugin and haven't used gdalwarp, but here:
>
>>>> I want to import it into a UTM zone 17 project. So I did the following:
>>>> gdalwarp -t_srs '+proj=utm +zone=17 +datum=WGS84' input.sid output_utm.sid
>
> it looks like you are just trying to create a new .sid file in zone 17 (output_utm.sid). From the meta file at the MI source, I think the file is already projected in utm - probably in zone 17, and with units of 'meters'. So what you maybe intended was to just create a .tiffg from the .sid so that it can be imported into GRASS.
>
> In mrsiddecode (the app that does all the work inside the plugin - I assume) I would just issue the command
>
> ./mrsiddecode -i Hancock.sid -o Hancock_south.tif -of tifg -ulxy 0 0 -lrxy 71145 29160
>
> where
>
> -i - input
> -o - output
> -of - output file type
> ulxy - upper left x,y
> lrxy - lower right x,y
>
> and you get a nice geotiff that r.in.gdal will recognize - already in utm zone 17 most likely. Actually, in my case, the OH mrsids are projected in state plane coordinates but you get the picture.
>
> To get the mrsiddecode app you must register at
>
> http://developer.lizardtech.com/
>
> so you can access to the Mac version of the decoder and mrsidinfo download page. And be slightly comfortable on the command line.
>
> Stu
>
>
Nope, that's not doing it. I downloaded mrsiddecode and ran it. It nicely generates a geotiff. But, if I try to import that I still get an error because the project is UTM, while the image is Oblique Mercator with omerc projection. I tried to use gdalwarp to go from the geotiff to utm, but I get an error:
gdalwarp -t_srs '+proj=utm +zone=17 +datum=WGS84' oak_grove_sw.tifg oak_grove_sw_utm.tifg
ERROR 1: latitude or longitude exceeded limits
ERROR 1: Too many points (441 out of 441) failed to transform,
unable to compute output bounds.
If I run gdalinfo on the geotiff I get it looks to me like the projection has lat long near 0. So, I don't think that the problem is a MrSID problem. But instead there is just something wrong with how I am doing the projection, or something is wrong with the file itself.
Here is the output of gdalinfo oak_grove_sw.tifg:
Driver: GTiff/GeoTIFF
Files: oak_grove_sw.tifg
Size is 6415, 8061
Coordinate System is:
PROJCS["Projection = Oblique Mercator (Hotine)",
GEOGCS["NAD83",
DATUM["North_American_Datum_1983",
SPHEROID["GRS 1980",6378137,298.2572221010002,
AUTHORITY["EPSG","7019"]],
AUTHORITY["EPSG","6269"]],
PRIMEM["Greenwich",0],
UNIT["degree",0.0174532925199433],
AUTHORITY["EPSG","4269"]],
PROJECTION["Hotine_Oblique_Mercator"],
PARAMETER["latitude_of_center",0.9996],
PARAMETER["longitude_of_center",0.9996],
PARAMETER["azimuth",0.9996],
PARAMETER["rectified_grid_angle",90],
PARAMETER["scale_factor",0.9996],
PARAMETER["false_easting",0.9996],
PARAMETER["false_northing",0.9996],
UNIT["metre",1,
AUTHORITY["EPSG","9001"]]]
Origin = (663144.500000000000000,240035.500000000000000)
Pixel Size = (1.000000000000000,-1.000000000000000)
Metadata:
AREA_OR_POINT=Area
Image Structure Metadata:
INTERLEAVE=PIXEL
Corner Coordinates:
Upper Left ( 663144.500, 240035.500) ( 6d57'27.03"E, 3d 9'14.09"N)
Lower Left ( 663144.500, 231974.500) ( 6d57'25.53"E, 3d 4'52.96"N)
Upper Right ( 669559.500, 240035.500) ( 7d 0'53.76"E, 3d 9'12.88"N)
Lower Right ( 669559.500, 231974.500) ( 7d 0'52.24"E, 3d 4'51.77"N)
Center ( 666352.000, 236005.000) ( 6d59'9.64"E, 3d 7'2.93"N)
Band 1 Block=6415x1 Type=Byte, ColorInterp=Red
Band 2 Block=6415x1 Type=Byte, ColorInterp=Green
Band 3 Block=6415x1 Type=Byte, ColorInterp=Blue
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