diff --git a/lib/mask.cpp b/lib/mask.cpp
new file mode 100644
index 0000000..bcb0c9b
--- /dev/null
+++ b/lib/mask.cpp
@@ -0,0 +1,24 @@
+#include "mask.h"
+#include <math.h>
+
+namespace Mask
+{
+
+	mask * createCircleMask(int size, bool gradient)
+	{
+		mask * newMask = new mask;
+		newMask->size = size;
+		newMask->mask = new uint8_t[size*size];
+		for (int x = 0; x < size; ++x)
+		{
+			for (int y = 0; y < size; ++y)
+			{
+				newMask->mask[y*size+x] = 
+					(sqrt( pow(x - x/2, 2) + pow(y - y/2, 2)) < size / 2)
+					? 255 : 0;
+			}
+		}
+		return newMask;
+	}
+
+}
diff --git a/lib/mask.h b/lib/mask.h
new file mode 100644
index 0000000..bcb4013
--- /dev/null
+++ b/lib/mask.h
@@ -0,0 +1,17 @@
+#ifndef _MASK_H_
+#define _MASK_H_
+
+#include <stdint.h>
+
+namespace Mask
+{
+	struct mask
+	{
+		int size;
+		uint8_t *mask;
+	};
+
+	mask * createCircleMask(int size, bool gradient = false);
+}
+
+#endif /* ifndef _MASK_H_ */