Followup: this issue may not apply to formats read by GDAL, since GDAL quietly promotes such files to 24 bit.
Ray Ray Gardener wrote:
Apparently reading of 16-bit images was not supported (a "bad enum 9" message would appear). The Targa format driver also did not read the alpha attribute in uncompressed 16-bit images. The fixes will be available in the next update.(Masked 16-bit Targa is rare, since it's only one opacity bit per pixel, but still.)Ray
