Hello, I am seeing that you are correct that the 'no data value' is being read in each case. Perhaps my interpretation of the problem appears incorrect.
Look, however at the 'Metadata:' statistics. Both files have assigned -999 to 'No Data Value' but 'STATISTICS_MINIMUM' for one file shows -999 (??). This means the values are not being ignored for the purpose of calculating statistics. --THE BAD FILE-- Band 2 Block=2178x1 Type=Float32, ColorInterp=Undefined Description = Band 2 Min=-999.000 Max=12.250 Minimum=-999.000, Maximum=12.250, Mean=-946.817, StdDev=222.404 NoData Value=-999 Metadata: STATISTICS_MINIMUM=-999 STATISTICS_MAXIMUM=12.25 STATISTICS_MEAN=-946.81678963104 STATISTICS_STDDEV=222.4036660914 ---THE GOOD FILE--- Band 2 Block=1677x1 Type=Float32, ColorInterp=Undefined Description = Band Math (Band Math (Band Math (1996_104 Landsat-4/5 TM :Surface Temperature Sensor:6:LSatThermalCube_96-98.img):LSatThermalCube_96-98_float.img):LSatThermalCube_96-98_float_cmsk.img) Min=0.250 Max=12.250 Minimum=0.250, Maximum=12.250, Mean=1.379, StdDev=0.995 NoData Value=-999 Metadata: STATISTICS_MINIMUM=0.25 STATISTICS_MAXIMUM=12.25 STATISTICS_MEAN=1.3787828985307 STATISTICS_STDDEV=0.99545771926881 Note the difference in stats calculations. Peter _______________________________________________ gdal-dev mailing list gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev