ecwfmeraster-conversion
I want to convert TIF to ECW with FME. Some tif-pixels have values of 255/255/255:
After conversion these pixels have values of 254/254/254 or 253/254/252 or similar.
How can I achieve that 255/255/255 is not changed?
I need 255/255/255 in result because I want to set the border of the image (255/255/255) to transparent in AutoCAD Map.
To convert TIF to ECW I use these FME tools:
Reader > RasterPaletteResolver > Writer
This message:
During translation, some features were read that did not match a reader feature type in the workspace. This can happen if the reader dataset is changed, or a reader feature type removed or renamed.
...should have nothing to do with how the data is written, just what is read. This FME Evangelist post should explain that part of the process.
With the attributes, one possible problem is that you aren't over-writing the original Geodatabase. ie once you run the workspace w/o creating the attributes, then future translations will never add them unless you overwrite the Geodatabase or at least drop the table. FME can create a table, but not modify one.
So, check in the Navigator window for a parameter to delete the geodatabase first, or open the Feature Type (table) properties dialog and click the Parameters tab for a parameter to drop the table first. Hopefully this will solve the problem.
GDAL (and therefore QGIS) can only read ECW files. ECW is a proprietary file format, and one needs to buy the ERDAS-ECW-JP2 SDK to be able to write files.
More details here.
Best Answer
This problem is addressed in part by http://blog.hexagongeospatial.com/help-ecw-speckled-edges/
The only way to achieve consistent background color values after compression is by using an AllOpacity band which doesn't appear to be supported by the version of ECWJP2 SDK used in FME.