diff --git a/src/Lib/HGT/draw_picture.pl b/src/Lib/HGT/draw_picture.pl
new file mode 100755
index 00000000..bddeea7d
--- /dev/null
+++ b/src/Lib/HGT/draw_picture.pl
@@ -0,0 +1,62 @@
+#!/usr/bin/perl
+
+use GD;
+
+$output = "picture.png";
+
+# load data
+$width = <>; chomp($width);
+$height = <>; chomp($height);
+$min = 9999;
+$max = -9999;
+
+for ( $i = 0; $i < $height; $i++ ) {
+    for ( $j = 0; $j < $width; $j++ ) {
+        $d = <>; chomp($d);
+        if ( $d < -9999 ) {
+            $d = 0;
+        }
+        if ( $d < $min ) {
+            $min = $d;
+        }
+        if ( $d > $max ) {
+            $max = $d;
+        }
+        $data{ "$i:$j" } = $d;
+    }
+}
+print "min = $min  max = $max\n";
+
+$im = new GD::Image( $width, $height );
+($w, $h) = $im->getBounds();
+print "create $w x $h\n";
+
+for ( $i = 0; $i < 255; $i++ ) {
+    $color{$i} = $im->colorAllocate( $i, $i, $i );
+}
+$red = $im->colorAllocate( 255, 10, 10 );
+
+# draw image
+for ( $i = 0; $i < $height; $i++ ) {
+    for ( $j = 0; $j < $width; $j++ ) {
+        if ( $data{ "$i:$j" } > 0 ) {
+            $level = 55 + int(200 * ( $data{ "$i:$j" } - $min ) / ( $max - $min ));
+        } else {
+            $level = 0;
+        }
+        
+        $im->setPixel( $j, $i, $color{$level} );
+    }
+}
+
+$im->line( 0, 0, $width, 0, $red );
+$im->line( 0, 1, $width, 1, $red );
+$im->line( 0, 2, $width, 2, $red );
+
+# write out gif
+$data = $im->png;
+open( OUTPUT, ">$output" ) ||
+    die "cannot open $output\n";
+binmode OUTPUT;
+print OUTPUT $data;
+close OUTPUT;