HFA reading code does not handle reduced precision properly

[sam.gillingham@…]

Frank,

I am having some trouble reading some compressed img files which I will attach
to this bug. One is float and the other signed 32 bit int. The central block of
each of these images is compressed using the 'reduced precision' system (numruns
= -1). I see this was added back in GDAL 1.1.5. However, the values GDAL reads
out are quite different from what Imagine displays - the numbers are huge for
floats and zero for ints where they should be more similar to the sorrounding
values. 

I had a quick look and couldn't see anything obvious in the reading code and I
couldn't find any documentation about the layout of reduced precision blocks. Do
you have additional documentation or any insight as to what could be going wrong?

Thanks,

Sam.

[sam.gillingham@…]

img files that demonstrate the problem