diff --git a/ChangeLog b/ChangeLog
index 84824819e..19532d0b4 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2003-08-07  Alexandre Duret-Lutz  <adl@gnu.org>
+
+	* wrap/python/cgi/ltl2tgba.in: Convert GIFs to PNGs.  Restrict
+	the size of dot's output to 1024x1024.
+	* src/tgbaalgos/dotty.cc (dotty_bfs::start): Do not preset
+	the size of the graph.  Set height=0 for the invisible state.
+
 2003-08-06  Alexandre Duret-Lutz  <adl@gnu.org>
 
 	* src/ltlparse/ltlparse.yy: Fix precedence OP_OR < OP_XOR < OP_AND.
diff --git a/src/tgbaalgos/dotty.cc b/src/tgbaalgos/dotty.cc
index 4d44990f9..2d6c0e07e 100644
--- a/src/tgbaalgos/dotty.cc
+++ b/src/tgbaalgos/dotty.cc
@@ -18,8 +18,7 @@ namespace spot
     start()
     {
       os_ << "digraph G {" << std::endl;
-      os_ << "  size=\"7.26,10.69\"" << std::endl;
-      os_ << "  0 [label=\"\", style=invis]" << std::endl;
+      os_ << "  0 [label=\"\", style=invis, height=0]" << std::endl;
       os_ << "  0 -> 1" << std::endl;
     }
 
diff --git a/wrap/python/cgi/README b/wrap/python/cgi/README
index 6360346d0..ce191c314 100644
--- a/wrap/python/cgi/README
+++ b/wrap/python/cgi/README
@@ -37,5 +37,8 @@ You have to install the script yourself if you want to test it.
    will run the script when the HTTP server processes the
    request.
 
-   ltl2tgba purges old files (>10min) from this directory 
+   ltl2tgba purges old files (>10min) from this directory
    each time it runs.
+
+4) `dot' from the GraphViz package, and `convert' from
+   the ImageMagick package should be in the PATH.
diff --git a/wrap/python/cgi/ltl2tgba.in b/wrap/python/cgi/ltl2tgba.in
index 7b33e0712..b3d5baf33 100644
--- a/wrap/python/cgi/ltl2tgba.in
+++ b/wrap/python/cgi/ltl2tgba.in
@@ -126,9 +126,11 @@ if show_formula_gif:
     outfile = spot.ofstream(imgprefix + '-f.dot')
     spot.dotty(outfile, f)
     del outfile
-    os.spawnlp(os.P_WAIT, 'dot', 'dot', '-Tgif', '-o',
+    os.spawnlp(os.P_WAIT, 'dot', 'dot', '-Tgif', '-Gsize=14,14', '-o',
                imgprefix + '-f.gif', imgprefix + '-f.dot')
-    print '<img src="' + imgprefix + '-f.gif">'
+    os.spawnlp(os.P_WAIT, 'convert', 'convert',
+               imgprefix + '-f.gif', imgprefix + '-f.png')
+    print '<img src="' + imgprefix + '-f.png">'
 
 
 print '<H2>Automaton</H2>'
@@ -155,9 +157,11 @@ if show_automaton_gif:
     outfile = spot.ofstream(imgprefix + '-a.dot')
     spot.dotty_reachable(outfile, concrete)
     del outfile
-    os.spawnlp(os.P_WAIT, 'dot', 'dot', '-Tgif', '-o',
+    os.spawnlp(os.P_WAIT, 'dot', 'dot', '-Tgif', '-Gsize=14,14', '-o',
 	       imgprefix + '-a.gif', imgprefix + '-a.dot')
-    print '<img src="' + imgprefix + '-a.gif">'
+    os.spawnlp(os.P_WAIT, 'convert', 'convert',
+               imgprefix + '-a.gif', imgprefix + '-a.png')
+    print '<img src="' + imgprefix + '-a.png">'
 
 
 if show_degen_dot or show_degen_gif:
@@ -174,9 +178,11 @@ if show_degen_dot or show_degen_gif:
 	outfile = spot.ofstream(imgprefix + '-d.dot')
 	spot.dotty_reachable(outfile, degen)
 	del outfile
-	os.spawnlp(os.P_WAIT, 'dot', 'dot', '-Tgif', '-o',
+	os.spawnlp(os.P_WAIT, 'dot', 'dot', '-Tgif', '-Gsize=14,14', '-o',
 		   imgprefix + '-d.gif', imgprefix + '-d.dot')
-	print '<img src="' + imgprefix + '-d.gif">'
+        os.spawnlp(os.P_WAIT, 'convert', 'convert',
+                   imgprefix + '-d.gif', imgprefix + '-d.png')
+	print '<img src="' + imgprefix + '-d.png">'
 else:
     degen = 0
 
@@ -200,9 +206,11 @@ if show_relation_dot or show_relation_set or show_relation_gif:
 	spot.bdd_print_dot(outfile, concrete.get_dict(),
 			   concrete.get_core_data().relation)
 	del outfile
-	os.spawnlp(os.P_WAIT, 'dot', 'dot', '-Tgif', '-o',
+	os.spawnlp(os.P_WAIT, 'dot', 'dot', '-Tgif', '-Gsize=14,14', '-o',
 		   imgprefix + '-b.gif', imgprefix + '-b.dot')
-	print '<img src="' + imgprefix + '-b.gif">'
+        os.spawnlp(os.P_WAIT, 'convert', 'convert',
+                   imgprefix + '-b.gif', imgprefix + '-b.png')
+	print '<img src="' + imgprefix + '-b.png">'
 
 if show_acceptance_dot or show_acceptance_set or show_acceptance_gif:
     print '<H3>Acceptance relation</H3>'
@@ -217,9 +225,11 @@ if show_acceptance_dot or show_acceptance_set or show_acceptance_gif:
 	spot.bdd_print_dot(outfile, concrete.get_dict(),
 			   concrete.get_core_data().accepting_conditions)
 	del outfile
-	os.spawnlp(os.P_WAIT, 'dot', 'dot', '-Tgif', '-o',
+	os.spawnlp(os.P_WAIT, 'dot', 'dot', '-Tgif', '-Gsize=14,14', '-o',
 		   imgprefix + '-c.gif', imgprefix + '-c.dot')
-	print '<img src="' + imgprefix + '-c.gif">'
+        os.spawnlp(os.P_WAIT, 'convert', 'convert',
+                   imgprefix + '-c.gif', imgprefix + '-c.png')
+	print '<img src="' + imgprefix + '-c.png">'
 
 if show_lbtt:
     print '<H3>LBTT conversion</H3>'