I am using GDAL (GDAL 1.9.2, released 2012/10/08) to change of EPSG referential on a GeoTiff file. I do the exact same command on two different computers (with the same version of GDAL and tiff libraries). And I get two different results... I am out of options, any idea ? Any place I should have a look ?
Command :
gdalwarp -s_srs EPSG:3975 -t_srs EPSG:4326 input.tif output.tif
Input file :
Driver: GTiff/GeoTIFF
Files: input.tif
Size is 1388, 584
Coordinate System is `'
Origin = (-17321655.543400000780821,7332251.365589999593794)
Pixel Size = (24959.157843515851710,-25110.449882157532556)
Metadata:
lat#_FillValue=9.96921e+36
lat#long_name=latitude
lat#units=degrees_north
lon#_FillValue=9.96921e+36
lon#long_name=longitude
lon#units=degrees_east
NC_GLOBAL#conventions=CF-1.4
NC_GLOBAL#creation_date=2014-10-20T16:12:01
NC_GLOBAL#datum=+ellps = WGS84
NC_GLOBAL#ease_global=yes
NC_GLOBAL#ease_origin_lat=-83.517136
NC_GLOBAL#ease_origin_lon=-179.87032
NC_GLOBAL#ease_projection=cylindrical
NC_GLOBAL#ease_resolution=25
NC_GLOBAL#grip_mapping=projection
NC_GLOBAL#history=none
NC_GLOBAL#institution=SMOS CATDS Processing Chain
NC_GLOBAL#netcdf_version_id=3.6.2
NC_GLOBAL#product_version=1.0
NC_GLOBAL#proj4text=+proj=cea +lon_0=0 +lat_ts=30 +x_0=0 +y_0=0 +ellps=WGS84 +units=m +no_defs
NC_GLOBAL#srid=EPSG:3975
Image Structure Metadata:
INTERLEAVE=BAND
Corner Coordinates:
Upper Left (-17321655.543, 7332251.366)
Lower Left (-17321655.543,-7332251.366)
Upper Right (17321655.543, 7332251.366)
Lower Right (17321655.543,-7332251.366)
Center ( 0.0000000, 0.0000000)
Band 1 Block=1388x1 Type=Float64, ColorInterp=Gray
On computer A (the result I am expecting) :
Driver: GTiff/GeoTIFF
Files: output.tif
Size is 1355, 657
Coordinate System is:
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"]]
Origin = (-179.524544819822239,87.025797325816669)
Pixel Size = (0.264973369536817,-0.264973369536817)
Metadata:
AREA_OR_POINT=Area
Image Structure Metadata:
INTERLEAVE=BAND
Corner Coordinates:
Upper Left (-179.5245448, 87.0257973) (179d31'28.36"W, 87d 1'32.87"N)
Lower Left (-179.5245448, -87.0617065) (179d31'28.36"W, 87d 3'42.14"S)
Upper Right ( 179.5143709, 87.0257973) (179d30'51.74"E, 87d 1'32.87"N)
Lower Right ( 179.5143709, -87.0617065) (179d30'51.74"E, 87d 3'42.14"S)
Center ( -0.0050870, -0.0179546) ( 0d 0'18.31"W, 0d 1' 4.64"S)
Band 1 Block=1355x1 Type=Float64, ColorInterp=Gray
On computer B (with the exact same input and command) :
Driver: GTiff/GeoTIFF
Files: output.tif
Size is 1358, 651
Coordinate System is:
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"]]
Origin = (-179.674959335984454,86.219877359659435)
Pixel Size = (0.264688310439600,-0.264688310439600)
Metadata:
AREA_OR_POINT=Area
Image Structure Metadata:
INTERLEAVE=BAND
Corner Coordinates:
Upper Left (-179.6749593, 86.2198774) (179d40'29.85"W, 86d13'11.56"N)
Lower Left (-179.6749593, -86.0922127) (179d40'29.85"W, 86d 5'31.97"S)
Upper Right ( 179.7717662, 86.2198774) (179d46'18.36"E, 86d13'11.56"N)
Lower Right ( 179.7717662, -86.0922127) (179d46'18.36"E, 86d 5'31.97"S)
Center ( 0.0484035, 0.0638323) ( 0d 2'54.25"E, 0d 3'49.80"N)
Band 1 Block=1358x1 Type=Float64, ColorInterp=Gray
Thanks to GDAL dev mailing list, I found the responsible :
On one side I had : proj-4 v7.0-1
On the other (on the computer with expecting results) : proj-4 v8.0-3
With proj-4 v8.0-3 on both computers, I get the same results.