[libcamera-devel] [PATCH v2 1/5] ipa: ipu3: agc: Drop kMaxLuminance constant

Laurent Pinchart laurent.pinchart at ideasonboard.com
Fri Nov 19 22:02:35 CET 2021


The kMaxLuminance constant is badly named, it's not a maximum luminance,
but the maximum integer value output by the AWB statistics engine for
per-channel averages. The constant is used in a single place, hardcoding
the value is actually more readable.

Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
Reviewed-by: Jean-Michel Hautbois <jeanmichel.hautbois at ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham at ideasonboard.com>
---
 src/ipa/ipu3/algorithms/agc.cpp | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/src/ipa/ipu3/algorithms/agc.cpp b/src/ipa/ipu3/algorithms/agc.cpp
index bd02c474611c..43a39ffd57d6 100644
--- a/src/ipa/ipu3/algorithms/agc.cpp
+++ b/src/ipa/ipu3/algorithms/agc.cpp
@@ -61,9 +61,6 @@ static constexpr double kEvGainTarget = 0.5;
 /* Number of frames to wait before calculating stats on minimum exposure */
 static constexpr uint32_t kNumStartupFrames = 10;
 
-/* Maximum luminance used for brightness normalization */
-static constexpr uint32_t kMaxLuminance = 255;
-
 /*
  * Normalized luma value target.
  *
@@ -298,8 +295,7 @@ double Agc::computeInitialY(IPAFrameContext &frameContext,
 		       greenSum * frameContext.awb.gains.green * .587 +
 		       blueSum * frameContext.awb.gains.blue * .114;
 
-	/* Return the normalized relative luminance. */
-	return Y_sum / (grid.height * grid.width) / kMaxLuminance;
+	return Y_sum / (grid.height * grid.width) / 255;
 }
 
 /**
-- 
Regards,

Laurent Pinchart



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