Read TIFFs with multiple floating-point samples

I propose to extend Commons Imaging to support reading TIFF files that contain floating-point formats that feature more than one sample.  The ability to support floating-point samples was introduced in  ISSUE-251.  But that implementation was limited to only those files that provided a single sample per raster cell (e.g. "a single sample per pixel"). The ability to read files with multiple samples per raster cell would extend the usefulness of the Commons Imaging API, particularly for geophysical applications.

If anyone knows of good sources for test TIFF files that use this format, please let me know.

Background

In addition to conventional image data, TIFF files can provide floating-point numerical information. This feature is often used for geophysical data (in GeoTIFF files), but can also be applied to other uses. Although the existing implementation can support files which give a single value per raster cell, there are some products that carry multiple samples per cell. Examples include products that give both a measured value and a corresponding accuracy estimate (i.e. 245.6 meters plus or minus 0.5 meters). Some geophysical products give vectors (gravitational potential, wind vectors, ocean currents, etc.).

Changes would involve extensions to the classes in the TIFF datareader package as well as the TiffRasterData class.