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-rw-r--r--src/ipa/simple/soft_simple.cpp35
1 files changed, 22 insertions, 13 deletions
diff --git a/src/ipa/simple/soft_simple.cpp b/src/ipa/simple/soft_simple.cpp
index a5bb2bbf..dbbeabbf 100644
--- a/src/ipa/simple/soft_simple.cpp
+++ b/src/ipa/simple/soft_simple.cpp
@@ -5,6 +5,8 @@
* Simple Software Image Processing Algorithm module
*/
+#include <numeric>
+#include <stdint.h>
#include <sys/mman.h>
#include <linux/v4l2-controls.h>
@@ -240,28 +242,35 @@ void IPASoftSimple::stop()
void IPASoftSimple::processStats(const ControlList &sensorControls)
{
+ SwIspStats::Histogram histogram = stats_->yHistogram;
+ if (ignoreUpdates_ > 0)
+ blackLevel_.update(histogram);
+ const uint8_t blackLevel = blackLevel_.get();
+ params_->blackLevel = blackLevel;
+
+ /*
+ * Black level must be subtracted to get the correct AWB ratios, they
+ * would be off if they were computed from the whole brightness range
+ * rather than from the sensor range.
+ */
+ const uint64_t nPixels = std::accumulate(
+ histogram.begin(), histogram.end(), 0);
+ const uint64_t offset = blackLevel * nPixels;
+ const uint64_t sumR = stats_->sumR_ - offset / 4;
+ const uint64_t sumG = stats_->sumG_ - offset / 2;
+ const uint64_t sumB = stats_->sumB_ - offset / 4;
+
/*
* Calculate red and blue gains for AWB.
* Clamp max gain at 4.0, this also avoids 0 division.
*/
- if (stats_->sumR_ <= stats_->sumG_ / 4)
- params_->gainR = 1024;
- else
- params_->gainR = 256 * stats_->sumG_ / stats_->sumR_;
-
- if (stats_->sumB_ <= stats_->sumG_ / 4)
- params_->gainB = 1024;
- else
- params_->gainB = 256 * stats_->sumG_ / stats_->sumB_;
+ params_->gainR = sumR <= sumG / 4 ? 1024 : 256 * sumG / sumR;
+ params_->gainB = sumB <= sumG / 4 ? 1024 : 256 * sumG / sumB;
/* Green gain and gamma values are fixed */
params_->gainG = 256;
params_->gamma = 0.5;
- if (ignoreUpdates_ > 0)
- blackLevel_.update(stats_->yHistogram);
- params_->blackLevel = blackLevel_.get();
-
setIspParams.emit();
/* \todo Switch to the libipa/algorithm.h API someday. */