y, for compilation, the following header files are
   assumed to be in /usr/include:
      jpeg:  jconfig.h
      png:   png.h, pngconf.h
      tiff:  tiff.h, tiffio.h

   If for some reason you do not want to link to specific libraries,
   even if you have them, stub files are included for the ten
   different output formats:
        bmp, jpeg, png, pnm, ps, pdf, tiff, gif, webp and jp2.
   For example, if you don't want to include the tiff library,
   in environ.h set:
       #define  HAVE_LIBTIFF   0
   