1 files changed, 33 insertions, 0 deletions
diff --git a/test/lps-roundtrip.test b/test/lps-roundtrip.test
new file mode 100755
index 00000000..24076ef1
--- /dev/null
+++ b/test/lps-roundtrip.test
@@ -0,0 +1,33 @@
+#! /bin/sh
+# This script tests: pbmtolps pstopnm
+# Also requires: gs pamdepth pamscale pnmcrop pnmpsnr pamfile
+
+# The ordinary round-trip does not work because of the way ghostscript
+# renders: a line is considered wider than a single pixel and all pixels
+# it touches are set to black if the output is PBM.  To work around this,
+# we tell pstopnm to output PGM at a high resolution (=large dpi value).
+
+tmpdir=${tmpdir:-/tmp}
+test_pgm=${tmpdir}/test.pgm
+test_ps=${tmpdir}/test.ps
+
+echo "Test 1.  Should print match"
+
+xysize=$(pamfile -size testgrid.pbm | awk '{print "-xsize="$1,"-ysize="$2}')
+pamdepth 255 testgrid.pbm > ${test_pgm}
+  
+pbmtolps -dpi 72 testgrid.pbm | tee ${test_ps} | \
+    pstopnm -dpi $((72*12)) -stdout -pgm | \
+    pnmcrop -white | pamscale ${xysize}  | \
+    pnmpsnr -target=30 - ${test_pgm}
+
+    # ghostscript version 8.71: pnmpsnr lumina 33.14dB
+
+
+echo "Test 2.  Should print 0"
+
+pbmtolps -dpi 72 < testgrid.pbm | sed 's/noname/testgrid.pbm/' | \
+    cmp -s ${test_ps} -
+    echo $?
+  
+rm ${test_pgm} ${test_ps}