-# if this fails, you need libmagickcore-6.q16-2-extra installed
-is(size("$outpath/10x-emptysquare.png"), "10x10");
-is(size("$outpath/12x-twopages.png"), "12x12");
-is(size("$outpath/16x-p1-twopages.png"), "16x2");
+ok(! -e "$outpath/30x-redsquare.png");
+ok($outhtml =~ /width="30" height="30".*expecting 30x30/);
+
+SKIP: {
+ skip "SVG support not installed (try libmagickcore-extra)", 1
+ unless $SVGS_WORK;
+ # if this fails, you need libmagickcore-6.q16-2-extra installed
+ is(size("$outpath/10x-bluesquare.png"), "10x10");
+}
+
+SKIP: {
+ skip "PDF support not installed (try ghostscript)", 2
+ unless $PDFS_WORK;
+ is(size("$outpath/12x-twopages.png"), "12x12");
+ is(size("$outpath/16x-p1-twopages.png"), "16x2");
+}
+
+ok($outhtml =~ /width="8" height="8".*expecting 8x8/);
+is(size("$outpath/x8-hello:world.png"), "8x8");
+is(size("$outpath/x4-a:b:c.png"), "4x4");
+is(size("$outpath/x6-a:b:c:d:e:f:g:h:i:j.png"), "6x6");