[gdal-dev] Gdalwarp Mercator problem
Geoff Shipton
geoff at tritonimaginginc.com
Thu Jul 12 17:58:46 PDT 2012
Hello again,
Been having good success reprojecting TIFs from/to various different
projections (UTMs, State Plane, Mercator etc.) but I have run into a
problem with gdalwarp generating a particular Mercator GeoTIFF. At the
bottom of the mail is the console output from three operations:
1. Gdalinfo output from the input, a standard UTM Zone 35N Geotiff
2. Gdalwarp output warping to a Mercator Projection.
3. Gdalinfo output from the resulting Tif.
Although the TIF image looks OK and is rotated about as you would expect, as
you can see there are some invalid fields in the output from step #3,
In case it helps the three Proj4 strings are:
"+proj=utm +zone=35 +datum=WGS84 +units=m +no_defs" (from the original TIF)
"+proj=merc +datum=WGS84 +lon_0=0 +lat_ts=41.5 +x_0=0 +y_0=2000000" (input
to gdawarp)
"+proj=merc +lon_0=0 +k=1 +x_0=-1.#IND +y_0=0 +datum=WGS84 +to_meter=0
+no_defs" (the proj4 string from the final TIF)
If it helps I can provide links to the TIF files.
Can anyone spot what I am doing wrong?
Many thanks,
Geoff
STEP#1:
----------------------------------------------------------------------------
--
gdalinfo -proj4 G:\Tifftest\Marmara\testTrans_0_TRANS.tif
Driver: GTiff/GeoTIFF
Files: G:\Tifftest\Marmara\testTrans_0_TRANS.tif
G:\Tifftest\Marmara\testTrans_0_TRANS.tfw
Size is 1030, 740
Coordinate System is:
PROJCS["WGS 84 / UTM zone 35N",
GEOGCS["WGS 84",
DATUM["WGS_1984",
SPHEROID["WGS 84",6378137,298.257223563,
AUTHORITY["EPSG","7030"]],
AUTHORITY["EPSG","6326"]],
PRIMEM["Greenwich",0],
UNIT["degree",0.0174532925199433],
AUTHORITY["EPSG","4326"]],
PROJECTION["Transverse_Mercator"],
PARAMETER["latitude_of_origin",0],
PARAMETER["central_meridian",27],
PARAMETER["scale_factor",0.9996],
PARAMETER["false_easting",500000],
PARAMETER["false_northing",0],
UNIT["metre",1,
AUTHORITY["EPSG","9001"]],
AUTHORITY["EPSG","32635"]]
PROJ.4 string is:
'+proj=utm +zone=35 +datum=WGS84 +units=m +no_defs '
Origin = (640314.119512796050000,4530851.144891739800000)
Pixel Size = (0.999893837330017,-0.999390728012785)
Metadata:
AREA_OR_POINT=Area
TIFFTAG_RESOLUTIONUNIT=2 (pixels/inch)
TIFFTAG_XRESOLUTION=96
TIFFTAG_YRESOLUTION=96
Image Structure Metadata:
INTERLEAVE=PIXEL
Corner Coordinates:
Upper Left ( 640314.120, 4530851.145) ( 28d39'58.54"E, 40d55' 0.27"N)
Lower Left ( 640314.120, 4530111.596) ( 28d39'57.94"E, 40d54'36.30"N)
Upper Right ( 641344.010, 4530851.145) ( 28d40'42.55"E, 40d54'59.63"N)
Lower Right ( 641344.010, 4530111.596) ( 28d40'41.94"E, 40d54'35.66"N)
Center ( 640829.065, 4530481.370) ( 28d40'20.24"E, 40d54'47.96"N)
Band 1 Block=1030x1 Type=Byte, ColorInterp=Red
Mask Flags: PER_DATASET ALPHA
Band 2 Block=1030x1 Type=Byte, ColorInterp=Green
Mask Flags: PER_DATASET ALPHA
Band 3 Block=1030x1 Type=Byte, ColorInterp=Blue
Mask Flags: PER_DATASET ALPHA
Band 4 Block=1030x1 Type=Byte, ColorInterp=Alpha
STEP#2
----------------------------------------------------------------------------
--
Gdalwarp -co TFW=YES -t_srs "+proj=merc +datum=WGS84 +lon_0=0 +lat_ts=41.5
+x_0=0 +y_0=20
00000" G:\Tifftest\Marmara\testTrans_0_TRANS.tif
G:\Tifftest\Marmara\test.tif
Creating output file that is 1044P x 759L.
Processing input file G:\Tifftest\Marmara\testTrans_0_TRANS.tif.
Using band 4 of source image as alpha.
Using band 4 of destination image as alpha.
0...10...20...30...40...50...60...70...80...90...100 - done.
STEP#3
----------------------------------------------------------------------------
---
gdalinfo -proj4 G:\Tifftest\Marmara\test.tif
Driver: GTiff/GeoTIFF
Files: G:\Tifftest\Marmara\test.tif
G:\Tifftest\Marmara\test.tfw
Size is 1044, 759
Coordinate System is:
PROJCS["unnamed",
GEOGCS["WGS 84",
DATUM["WGS_1984",
SPHEROID["WGS 84",6378137,298.257223563,
AUTHORITY["EPSG","7030"]],
AUTHORITY["EPSG","6326"]],
PRIMEM["Greenwich",0],
UNIT["degree",0.0174532925199433],
AUTHORITY["EPSG","4326"]],
PROJECTION["Mercator_1SP"],
PARAMETER["central_meridian",0],
PARAMETER["scale_factor",1],
PARAMETER["false_easting","-1.#IND"],
PARAMETER["false_northing","1.#INF"],
UNIT["degree minute second hemisphere",0,
AUTHORITY["EPSG","9108"]]]
PROJ.4 string is:
'+proj=merc +lon_0=0 +k=1 +x_0=-1.#IND +y_0=0 +datum=WGS84 +to_meter=0
+no_defs
'
Origin = (2393508.975926194800000,5729350.050399892000000)
Pixel Size = (0.990987191737565,-0.990987191737565)
Metadata:
AREA_OR_POINT=Area
Image Structure Metadata:
INTERLEAVE=PIXEL
Corner Coordinates:
Upper Left ( 2393508.976, 5729350.050) ( 0d 0' 0.03"E, 0d 0' 0.01"N)
Lower Left ( 2393508.976, 5728597.891) ( 0d 0' 0.03"E, 0d 0' 0.01"N)
Upper Right ( 2394543.567, 5729350.050) ( 0d 0' 0.03"E, 0d 0' 0.01"N)
Lower Right ( 2394543.567, 5728597.891) ( 0d 0' 0.03"E, 0d 0' 0.01"N)
Center ( 2394026.271, 5728973.971) ( 0d 0' 0.03"E, 0d 0' 0.01"N)
Band 1 Block=1044x1 Type=Byte, ColorInterp=Red
Mask Flags: PER_DATASET ALPHA
Band 2 Block=1044x1 Type=Byte, ColorInterp=Green
Mask Flags: PER_DATASET ALPHA
Band 3 Block=1044x1 Type=Byte, ColorInterp=Blue
Mask Flags: PER_DATASET ALPHA
Band 4 Block=1044x1 Type=Byte, ColorInterp=Alpha
Geoff Shipton,
Triton Imaging Inc.
Customer Support.
Capitola CA.
<mailto:geoff at tritonimaginginc.com> geoff at tritonimaginginc.com
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