diff options
| -rw-r--r-- | src/ipa/ipu3/algorithms/awb.cpp | 27 | ||||
| -rw-r--r-- | src/ipa/ipu3/algorithms/awb.h | 1 |
2 files changed, 23 insertions, 5 deletions
diff --git a/src/ipa/ipu3/algorithms/awb.cpp b/src/ipa/ipu3/algorithms/awb.cpp index 5c232d92..70426722 100644 --- a/src/ipa/ipu3/algorithms/awb.cpp +++ b/src/ipa/ipu3/algorithms/awb.cpp @@ -409,6 +409,23 @@ constexpr uint16_t Awb::threshold(float value) return value * 8191; } +constexpr uint16_t Awb::gainValue(double gain) +{ + /* + * The colour gains applied by the BNR for the four channels (Gr, R, B + * and Gb) are expressed in the parameters structure as 16-bit integers + * that store a fixed-point U3.13 value in the range [0, 8[. + * + * The real gain value is equal to the gain parameter plus one, i.e. + * + * Pout = Pin * (1 + gain / 8192) + * + * where 'Pin' is the input pixel value, 'Pout' the output pixel value, + * and 'gain' the gain in the parameters structure as a 16-bit integer. + */ + return std::clamp((gain - 1.0) * 8192, 0.0, 65535.0); +} + /** * \copydoc libcamera::ipa::Algorithm::prepare */ @@ -450,11 +467,11 @@ void Awb::prepare(IPAContext &context, ipu3_uapi_params *params) * params->acc_param.bnr.opt_center.x_reset; params->acc_param.bnr.opt_center_sqr.y_sqr_reset = params->acc_param.bnr.opt_center.y_reset * params->acc_param.bnr.opt_center.y_reset; - /* Convert to u3.13 fixed point values */ - params->acc_param.bnr.wb_gains.gr = 8192 * context.activeState.awb.gains.green; - params->acc_param.bnr.wb_gains.r = 8192 * context.activeState.awb.gains.red; - params->acc_param.bnr.wb_gains.b = 8192 * context.activeState.awb.gains.blue; - params->acc_param.bnr.wb_gains.gb = 8192 * context.activeState.awb.gains.green; + + params->acc_param.bnr.wb_gains.gr = gainValue(context.activeState.awb.gains.green); + params->acc_param.bnr.wb_gains.r = gainValue(context.activeState.awb.gains.red); + params->acc_param.bnr.wb_gains.b = gainValue(context.activeState.awb.gains.blue); + params->acc_param.bnr.wb_gains.gb = gainValue(context.activeState.awb.gains.green); LOG(IPU3Awb, Debug) << "Color temperature estimated: " << asyncResults_.temperatureK; diff --git a/src/ipa/ipu3/algorithms/awb.h b/src/ipa/ipu3/algorithms/awb.h index 9a50a985..0acd2148 100644 --- a/src/ipa/ipu3/algorithms/awb.h +++ b/src/ipa/ipu3/algorithms/awb.h @@ -73,6 +73,7 @@ private: void awbGreyWorld(); uint32_t estimateCCT(double red, double green, double blue); static constexpr uint16_t threshold(float value); + static constexpr uint16_t gainValue(double gain); std::vector<RGB> zones_; Accumulator awbStats_[kAwbStatsSizeX * kAwbStatsSizeY]; |