[libcamera-devel,v5,10/19] ipa: ipu3: tonemapping: Add the documentation for ToneMapping
diff mbox series

Message ID 20211026112340.110169-11-jeanmichel.hautbois@ideasonboard.com
State Accepted
Commit a1f0df865409fa2d65e42ab7451fdfc98089c760
Headers show
Series
  • Document IPU3 IPA
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Commit Message

Jean-Michel Hautbois Oct. 26, 2021, 11:23 a.m. UTC 
The tone mapping algorithm is currently undocumented.

Provide an introduction and overview to the implementation as the class
definition and document how the algorithm operates in the process and
prepare methods.

Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com>
Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

---
v3:
- rename gamma control as tone mapping
---
 src/ipa/ipu3/algorithms/tone_mapping.cpp | 30 +++++++++++++++++++++++-
 1 file changed, 29 insertions(+), 1 deletion(-)

Patch
diff mbox series 

diff --git a/src/ipa/ipu3/algorithms/tone_mapping.cpp b/src/ipa/ipu3/algorithms/tone_mapping.cpp
index fcd22d0b..2040eda5 100644
--- a/src/ipa/ipu3/algorithms/tone_mapping.cpp
+++ b/src/ipa/ipu3/algorithms/tone_mapping.cpp
@@ -10,10 +10,22 @@ 
 #include <cmath>
 #include <string.h>
 
+/**
+ * \file tone_mapping.h
+ */
+
 namespace libcamera {
 
 namespace ipa::ipu3::algorithms {
 
+/**
+ * \class ToneMapping
+ * \brief A class to handle tone mapping based on gamma
+ *
+ * This algorithm improves the image dynamic using a look-up table which is
+ * generated based on a gamma parameter.
+ */
+
 ToneMapping::ToneMapping()
 	: gamma_(1.0)
 {
@@ -35,6 +47,14 @@  int ToneMapping::configure(IPAContext &context,
 	return 0;
 }
 
+/**
+ * \brief Fill in the parameter structure, and enable gamma control
+ * \param context The shared IPA context
+ * \param params The IPU3 parameters
+ *
+ * Populate the IPU3 parameter structure with our tone mapping look up table and
+ * enable the gamma control module in the processing blocks.
+ */
 void ToneMapping::prepare([[maybe_unused]] IPAContext &context,
 			  ipu3_uapi_params *params)
 {
@@ -49,7 +69,15 @@  void ToneMapping::prepare([[maybe_unused]] IPAContext &context,
 	params->acc_param.gamma.gc_ctrl.enable = 1;
 }
 
-void ToneMapping::process([[maybe_unused]] IPAContext &context,
+/**
+ * \brief Calculate the tone mapping look up table
+ * \param context The shared IPA context
+ * \param stats The IPU3 statistics and ISP results
+ *
+ * The tone mapping look up table is generated as an inverse power curve from
+ * our gamma setting.
+ */
+void ToneMapping::process(IPAContext &context,
 			  [[maybe_unused]] const ipu3_uapi_stats_3a *stats)
 {
 	/*