diff --git a/testdata/invert.png b/testdata/invert.png
new file mode 100644
index 0000000..7032005
Binary files /dev/null and b/testdata/invert.png differ
diff --git a/testdata/lena.png b/testdata/lena.png
deleted file mode 100644
index 59ef68a..0000000
Binary files a/testdata/lena.png and /dev/null differ