libipa: lux: Normalize referenceY to 1

By normalizing the referenceY value to 1 (which is the usual range for
Y) in the tuning file, the bins_ value is no longer needed. Remove it.

Signed-off-by: Stefan Klug <stefan.klug@ideasonboard.com>
Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
Reviewed-by: Daniel Scally <dan.scally@ideasonboard.com>
Reviewed-by: Daniel Scally <dan.scally@ideasonboard.com>

3 files changed, 7 insertions, 20 deletions

diff --git a/src/ipa/libipa/lux.cpp b/src/ipa/libipa/lux.cpp
index 61f8fea8..899e8824 100644
--- a/src/ipa/libipa/lux.cpp
+++ b/src/ipa/libipa/lux.cpp
@@ -44,11 +44,6 @@ namespace ipa {
  */
 
 /**
- * \var Lux::binSize_
- * \brief The maximum count of each bin
- */
-
-/**
  * \var Lux::referenceExposureTime_
  * \brief The exposure time of the reference image, in microseconds
  */
@@ -65,9 +60,8 @@ namespace ipa {
 
 /**
  * \var Lux::referenceY_
- * \brief The measured luminance of the reference image, out of the bin size
+ * \brief The measured luminance of the reference image, normalized to 1
  *
- * \sa binSize_
  */
 
 /**
@@ -76,11 +70,9 @@ namespace ipa {
  */
 
 /**
- * \brief Construct the Lux helper module
- * \param[in] binSize The maximum count of each bin
- */
-Lux::Lux(unsigned int binSize)
-	: binSize_(binSize)
+  * \brief Construct the Lux helper module
+  */
+Lux::Lux()
 {
 }
 
@@ -97,7 +89,7 @@ Lux::Lux(unsigned int binSize)
  *       referenceExposureTime: 10000
  *       referenceAnalogueGain: 4.0
  *       referenceDigitalGain: 1.0
- *       referenceY: 12000
+ *       referenceY: 0.1831
  *       referenceLux: 1000
  * \endcode
  *
@@ -167,7 +159,7 @@ double Lux::estimateLux(utils::Duration exposureTime,
 	double exposureTimeRatio = referenceExposureTime_ / exposureTime;
 	double aGainRatio = referenceAnalogueGain_ / aGain;
 	double dGainRatio = referenceDigitalGain_ / dGain;
-	double yRatio = currentY * (binSize_ / yHist.bins()) / referenceY_;
+	double yRatio = (currentY / yHist.bins()) / referenceY_;
 
 	double estimatedLux = exposureTimeRatio * aGainRatio * dGainRatio *
 			      yRatio * referenceLux_;
diff --git a/src/ipa/libipa/lux.h b/src/ipa/libipa/lux.h
index 93ca6479..d95bcdaf 100644
--- a/src/ipa/libipa/lux.h
+++ b/src/ipa/libipa/lux.h
@@ -21,7 +21,7 @@ class Histogram;
 class Lux
 {
 public:
-	Lux(unsigned int binSize);
+	Lux();
 
 	int parseTuningData(const YamlObject &tuningData);
 	double estimateLux(utils::Duration exposureTime,
@@ -29,7 +29,6 @@ public:
 			   const Histogram &yHist) const;
 
 private:
-	unsigned int binSize_;
 	utils::Duration referenceExposureTime_;
 	double referenceAnalogueGain_;
 	double referenceDigitalGain_;
diff --git a/src/ipa/rkisp1/algorithms/lux.cpp b/src/ipa/rkisp1/algorithms/lux.cpp
index b0f74963..a467767e 100644
--- a/src/ipa/rkisp1/algorithms/lux.cpp
+++ b/src/ipa/rkisp1/algorithms/lux.cpp
@@ -33,12 +33,8 @@ namespace ipa::rkisp1::algorithms {
 
 /**
  * \brief Construct an rkisp1 Lux algo module
- *
- * The Lux helper is initialized to 65535 as that is the max bin count on the
- * rkisp1.
  */
 Lux::Lux()
-	: lux_(65535)
 {
 }