2003.12.04 21:11 "[Tiff] Double Precision TIFF images", by Antonio Scuri
Could you check that image? The Photometric is BlackIsZero, but I guess
it should be RGB.
It is interesting that BitsPerSample and SampleFormat have 3 values, and the file size is also compatible with a RGB double image.
I have prepared a smallish sample for you in double precision at: