LOCI_oib2tiff.txt is an ImageJ/FIJI macro. It will batch convert .oib files in a source directory and store the TIFF files in a destination directory. It will generate either grayscale TIFFs, or hyperstack composites, or single TIFF RGB files.

Download the text file, then use Plugings->Macros->Run... to run it from within ImageJ or FIJI.