diff options
| -rw-r--r-- | src/ipa/raspberrypi/controller/rpi/agc.cpp | 25 |
1 files changed, 15 insertions, 10 deletions
diff --git a/src/ipa/raspberrypi/controller/rpi/agc.cpp b/src/ipa/raspberrypi/controller/rpi/agc.cpp index 9a5d84f7..f0c70a0a 100644 --- a/src/ipa/raspberrypi/controller/rpi/agc.cpp +++ b/src/ipa/raspberrypi/controller/rpi/agc.cpp @@ -385,18 +385,23 @@ static double compute_initial_Y(bcm2835_isp_stats *stats, Metadata *image_metada awb.gain_r = awb.gain_g = awb.gain_b = 1.0; // in case no metadata if (image_metadata->Get("awb.status", awb) != 0) LOG(RPiAgc, Warning) << "Agc: no AWB status found"; - double Y_sum = 0, weight_sum = 0; + // Note how the calculation below means that equal weights give you + // "average" metering (i.e. all pixels equally important). + double R_sum = 0, G_sum = 0, B_sum = 0, pixel_sum = 0; for (int i = 0; i < AGC_STATS_SIZE; i++) { - if (regions[i].counted == 0) - continue; - weight_sum += weights[i]; - double Y = regions[i].r_sum * awb.gain_r * .299 + - regions[i].g_sum * awb.gain_g * .587 + - regions[i].b_sum * awb.gain_b * .114; - Y /= regions[i].counted; - Y_sum += Y * weights[i]; + R_sum += regions[i].r_sum * weights[i]; + G_sum += regions[i].g_sum * weights[i]; + B_sum += regions[i].b_sum * weights[i]; + pixel_sum += regions[i].counted * weights[i]; } - return Y_sum / weight_sum / (1 << PIPELINE_BITS); + if (pixel_sum == 0.0) { + LOG(RPiAgc, Warning) << "compute_initial_Y: pixel_sum is zero"; + return 0; + } + double Y_sum = R_sum * awb.gain_r * .299 + + G_sum * awb.gain_g * .587 + + B_sum * awb.gain_b * .114; + return Y_sum / pixel_sum / (1 << PIPELINE_BITS); } // We handle extra gain through EV by adjusting our Y targets. However, you |