I'd say ImageMagick sets the standard here. Please use mupdf/ sub directory for the headers. See bug 503690
In fact, let me take a closer look first. $ grep -r -i fitz * configure: ac_fn_c_check_header_mongrel "$LINENO" "mupdf/fitz.h" "ac_cv_header_mupdf_fitz_h" "$ac_includes_default" configure:if test "x$ac_cv_header_mupdf_fitz_h" = xyes; then : configure.ac: AC_CHECK_HEADER(mupdf/fitz.h,passed=`expr $passed + 1`,failed=`expr $failed + 1`,) Only in configure.ac?
I should have looked, they ARE in the mupdf/ sub directory at least in version 1.3