ImageBufAlgo::rangecompress()/rangexpand() compress the range of data
values in an image by keeping values <= 1.0 as they are but rescaling
values > 1.0 to be on a log scale (with a smooth transition between
them.
oiiotool --rangeexpand, --rangecompress
maketx --hicomp performs hilight compensation, a combination of range
compression/expansion and clamping negative values to zero, surrounding
every resize step.