If you are unable to persuade your system administrator to install Motif, or you wish to use a different Motif such as Lesstif, the Motif libraries and include files may be installed under the tnimage source directory in directories named ``./include'' and ``./libs'', or ``./motif/include/Motif-2.0'' and ``./motif/lib/Xm-2.0/.libs''. The latter is primarily useful with systems in which Lesstif is to coexist with another Motif. In this case only, edit the file makefile-lesstif as necessary and compile tnimage with the command make -f makefile-lesstif .
If the program does not compile with Lesstif, one possible reason is that Lesstif Motif-2.0 is installed, which is missing some constants and functions found in other more 2.0-compliant Motifs. This can be fixed by editing config.h and commenting out the line #define MOTIF2 1 by changing it to /* #define MOTIF2 1 */ and recompiling (without re-running configure).
Please notify me if you have problems after compiling with Lesstif. Otherwise, it may be a very long time before the problem gets fixed, since I only occasionally test the program with Lesstif.