diff --git a/CONTRIBUTORS.txt b/CONTRIBUTORS.txt
index 9f3f2aa7..d582ab63 100644
--- a/CONTRIBUTORS.txt
+++ b/CONTRIBUTORS.txt
@@ -129,3 +129,6 @@
 
 - Anders Boesen Lindbo Larsen
   Dense DAISY feature description, circle perimeter drawing.
+
+- François Boulogne
+  Andres Method for circle perimeter, ellipse perimeter drawing.