We created XnView plugin for viewing terrain elevation maps (raw or srtm files) to help us visualize input heightfield data in any combination of format (8-, 16- or 32-bit depth, signed or unsigned, integer or floating point, endianness etc.).
The plugin also autodetects image dimensions by computing row correlation coefficient for all possible image dimensions (i.e. the dimensions that give the correct file size for specified image options)
Find it here.