diff --git a/doc/pattern.pdf b/doc/pattern.pdf
deleted file mode 100644
index d310f3ece4..0000000000
Binary files a/doc/pattern.pdf and /dev/null differ
diff --git a/doc/pattern.png b/doc/pattern.png
new file mode 100644
index 0000000000..5227c91871
Binary files /dev/null and b/doc/pattern.png differ