1 files changed, 23 insertions, 0 deletions
diff --git a/src/ipa/rpi/controller/lux_status.h b/src/ipa/rpi/controller/lux_status.h
new file mode 100644
index 00000000..5eb9faac
--- /dev/null
+++ b/src/ipa/rpi/controller/lux_status.h
@@ -0,0 +1,23 @@
+/* SPDX-License-Identifier: BSD-2-Clause */
+/*
+ * Copyright (C) 2019, Raspberry Pi Ltd
+ *
+ * lux_status.h - Lux control algorithm status
+ */
+#pragma once
+
+/*
+ * The "lux" algorithm looks at the (AGC) histogram statistics of the frame and
+ * estimates the current lux level of the scene. It does this by a simple ratio
+ * calculation comparing to a reference image that was taken in known conditions
+ * with known statistics and a properly measured lux level. There is a slight
+ * problem with aperture, in that it may be variable without the system knowing
+ * or being aware of it. In this case an external application may set a
+ * "current_aperture" value if it wishes, which would be used in place of the
+ * (presumably meaningless) value in the image metadata.
+ */
+
+struct LuxStatus {
+	double lux;
+	double aperture;
+};