MATLAB: How to write 32-bit floating point TIFs with NaNs

Question

I'm able to use IMREAD to read 32-bit floating point TIFs with NaNs for dead pixels.

After this, I do an image rotation with IMTRANSFORM with 'FillValue' of NaN (IMROTATE only fills with zeros).

Now, I'd like to save 32-bit floating point TIFs with NaNs in tact for later.

How can I do this? I've tried IMWRITE and MULTIBANDWRITE, but they don't seem to work.

I'm using MATLAB 7.11.0 (R2010b).

Thanks,

Kevin Crosby

Answer 1

I suggest using the Tiff class and specifying RGB for the Photometric and specifying 32 bits per channel and writing single precision values.

http://www.mathworks.com/help/matlab/ref/tiff-class.html

This is based upon the assumption that you want the channel values themselves to be NaN, rather than setting the Alpha value to be NaN for the dead pixels.