I am trying to generate GeoTiff rasters using FME Desktop 2015.1. My input is an 8 bit raster that has areas with pixel values of 0 around its edges. I want to set these to NoData.
I tried using the RasterBandNodataSetter to set the values to NoData. This was technically successful but pixels with a value of 0 in the middle of my raster were set to NoData as well which is not what I want.
I have also experimented with using the clipper to extract the areas I want hoping that the areas I do not extract would be set to NoData. However the clipper transformer uses the rectangular extent of my clipper feature to clip while I need it to be tapered to the extent of my study area.
I have also tried to write an alpha8 band to the GeoTiff in addition to my main Gray8 band. I was hoping to set the alpha8 to 0 where there is no data so nothing would be displayed. However the GeoTiff writer seems to insist on turning by alpha8 band into a UINT8.
What is the best approach to achieve this?