Steve Ansari wrote:
Yuan,
I'm not using greyscale. I've printed out the max and min values from
the section of GeotiffWriter.java that sets the tag values to verify
that the correct max/min values are calculated. It appears that they
are.
MAMath.MinMax dataMinMax = grid.getMinMaxSkipMissingData( data);
float min = (float) (dataMinMax.min);
float max = (float) (dataMinMax.max);
System.out.println(min+","+max); geotiff.addTag( new
IFDEntry(Tag.SMinSampleValue, FieldType.FLOAT).setValue( min));
geotiff.addTag( new IFDEntry(Tag.SMaxSampleValue,
FieldType.FLOAT).setValue( max));
Thanks,
Steve
Steve,
I know why now. It is because of the missing value -999.0.
When we calculated the min and max, we skipped the missing value,
and Arcmap does not look at the min/max tags, or finds the confliction
of tags and data value and takes actual data value -999.0.
Yuan
Yuan Ho wrote:
Steve Ansari wrote:
Hi John,
I did have one other question...
I've been exporting GeoTIFFs from NetCDF files using the
ucar.nc2.geotiff.GeotiffWriter class. When I load the images in
ESRI ArcMap the default max and min values are incorrect. Ex)
High : 3.40282e+038
Low : 1.17549e-038
Steve,
Is the output file greyscale? Otherwise the min and max value
should be stored in these two tags: Tag.SMinSampleValue and
Tag.SMaxSampleValue.
Let me know how do you get these High and Low values, and what are
the values of above two tags.
Yuan
The actual data values are ok and the image is correctly
geolocated. It seems that there may be max/min header or tag
information that may be missing.
Thanks,
Steve
