[PATCH 10/10] ipa: rkisp1: awb: Avoid division by zero

Stefan Klug stefan.klug at ideasonboard.com
Mon Feb 17 11:01:51 CET 2025


As the gains can also be specified manually, the regulation can run
into numeric instabilities by dividing by near zero. Mitigate that by applying a small minium value.

Signed-off-by: Stefan Klug <stefan.klug at ideasonboard.com>
---
 src/ipa/rkisp1/algorithms/awb.cpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/ipa/rkisp1/algorithms/awb.cpp b/src/ipa/rkisp1/algorithms/awb.cpp
index 66e6aecedc4c..6315d2adaad9 100644
--- a/src/ipa/rkisp1/algorithms/awb.cpp
+++ b/src/ipa/rkisp1/algorithms/awb.cpp
@@ -310,9 +310,9 @@ void Awb::process(IPAContext &context,
 	/*
 	 * The ISP computes the AWB means after applying the colour gains,
 	 * divide by the gains that were used to get the raw means from the
-	 * sensor.
+	 * sensor. Apply a minimum value to avoid divisions by near-zero.
 	 */
-	rgbMeans /= frameContext.awb.gains;
+	rgbMeans /= frameContext.awb.gains.max(0.01);
 
 	/*
 	 * If the means are too small we don't have enough information to
-- 
2.43.0



More information about the libcamera-devel mailing list