[{"id":20829,"web_url":"https://patchwork.libcamera.org/comment/20829/","msgid":"<163658335669.2121661.10867876860392000584@Monstersaurus>","date":"2021-11-10T22:29:16","subject":"Re: [libcamera-devel] [PATCH v2 07/14] ipa: ipu3: agc: Improve gain\n\tcalculation","submitter":{"id":4,"url":"https://patchwork.libcamera.org/api/people/4/","name":"Kieran Bingham","email":"kieran.bingham@ideasonboard.com"},"content":"Quoting Jean-Michel Hautbois (2021-11-10 19:58:54)\n> When an image is partially saturated, its brightness is not increasing\n> linearly when the shutter time or gain increases. It is a big issue with\n> a backlight as the algorithm is fading to darkness right now.\n> \n> Introduce a function to estimate the brightness of the frame, based on\n> the current exposure/gain and loop on it several times to estimate it\n> again and approach the non linear function.\n> \n> Inspired-by: 7de5506c30b3 (\"libcamera: src: ipa: raspberrypi: agc: Improve gain update calculation for partly saturated images\")\n> Signed-off-by: Jean-Michel Hautbois \n> ---\n> src/ipa/ipu3/algorithms/agc.cpp | 103 +++++++++++++++++++++++++++++++-\n> src/ipa/ipu3/algorithms/agc.h | 6 +-\n> 2 files changed, 105 insertions(+), 4 deletions(-)\n> \n> diff --git a/src/ipa/ipu3/algorithms/agc.cpp b/src/ipa/ipu3/algorithms/agc.cpp\n> index 119a7938..ee37a9d5 100644\n> --- a/src/ipa/ipu3/algorithms/agc.cpp\n> +++ b/src/ipa/ipu3/algorithms/agc.cpp\n> @@ -67,6 +67,9 @@ static constexpr uint32_t kMinCellsPerZoneRatio = 255 * 20 / 100;\n> /* Number of frames to wait before calculating stats on minimum exposure */\n> static constexpr uint32_t kNumStartupFrames = 10;\n> \n> +/* Maximum luminance used for brightness normalization */\n> +static constexpr uint32_t kMaxLuminance = 255;\n> +\n> Agc::Agc()\n> : frameCount_(0), iqMean_(0.0), lineDuration_(0s), minExposureLines_(0),\n> maxExposureLines_(0), filteredExposure_(0s), currentExposure_(0s),\n> @@ -186,10 +189,16 @@ void Agc::filterExposure()\n> * \\brief Estimate the new exposure and gain values\n> * \\param[inout] exposure The exposure value reference as a number of lines\n> * \\param[inout] gain The gain reference to be updated\n> + * \\param[in] currentYGain The gain calculated on the current brightness level\n> */\n> -void Agc::computeExposure(uint32_t &exposure, double &analogueGain)\n> +void Agc::computeExposure(uint32_t &exposure, double &analogueGain, double currentYGain)\n> {\n> - /* Estimate the gain needed to have the proportion wanted */\n> + /*\n> + * Estimate the gain needed to have the proportion of pixels in a given\n> + * range wanted. iqMean_ returns the mean value of the top 2% of the\n> + * cumulative histogram, and we want it to be as close as possible to a\n> + * configured target.\n> + */\n> double evGain = kEvGainTarget * knumHistogramBins / iqMean_;\n> \n> if (std::abs(evGain - 1.0) < 0.01) {\n> @@ -199,6 +208,7 @@ void Agc::computeExposure(uint32_t &exposure, double &analogueGain)\n> }\n> \n> /* extracted from Rpi::Agc::computeTargetExposure */\n> +\n> /* Calculate the shutter time in seconds */\n> utils::Duration currentShutter = exposure * lineDuration_;\n> LOG(IPU3Agc, Debug) << \"Actual total exposure \" << currentShutter * analogueGain\n> @@ -206,6 +216,14 @@ void Agc::computeExposure(uint32_t &exposure, double &analogueGain)\n> << \" Gain \" << analogueGain\n> << \" Needed ev gain \" << evGain;\n> \n> + if (evGain < currentYGain)\n> + evGain = currentYGain;\n> +\n> + /* Consider within 1% of the target as correctly exposed */\n> + if (std::abs(evGain - 1.0) < 0.01)\n> + LOG(IPU3Agc, Debug) << \"We are well exposed (iqMean = \"\n> + << iqMean_ << \")\";\n> +\n> /*\n> * Calculate the current exposure value for the scene as the latest\n> * exposure value applied multiplied by the new estimated gain.\n> @@ -253,6 +271,57 @@ void Agc::computeExposure(uint32_t &exposure, double &analogueGain)\n> prevExposureValue_ = shutterTime * analogueGain;\n> }\n> \n> +/**\n> + * \\brief Estimate the average brightness of the frame\n> + * \\param[in] context The shared IPA context\n\nframeContext?\n\n> + * \\param[in] grid The grid used to store the statistics in the IPU3\n> + * \\param[in] stats The IPU3 statistics and ISP results\n> + * \\param[in] currentYGain The gain calculated on the current brightness level\n> + * \\return The normalized luma\n> + *\n> + * Luma is the weighted sum of gamma-compressed R′G′B′ components of a color\n> + * video. The luma values are normalized as 0.0 to 1.0, with 1.0 being a\n> + * theoretical perfect reflector of 100% reference white. We use the Rec. 601\n> + * luma here.\n> + *\n> + * More detailed information can be found in:\n> + * https://en.wikipedia.org/wiki/Luma_(video)\n\nThank you - that all helps a lot in making it understandable (and being\nexplicit about where these conversions are from/represent).\n\n\n> + */\n> +double Agc::computeInitialY(IPAFrameContext &frameContext,\n> + const ipu3_uapi_grid_config &grid,\n> + const ipu3_uapi_stats_3a *stats,\n> + double currentYGain)\n> +{\n> + double redSum = 0, greenSum = 0, blueSum = 0;\n> +\n> + for (unsigned int cellY = 0; cellY < grid.height; cellY++) {\n> + for (unsigned int cellX = 0; cellX < grid.width; cellX++) {\n> + uint32_t cellPosition = cellY * stride_ + cellX;\n> +\n> + const ipu3_uapi_awb_set_item *cell =\n> + reinterpret_cast(\n> + &stats->awb_raw_buffer.meta_data[cellPosition]\n> + );\n> +\n> + redSum += cell->R_avg * currentYGain;\n> + greenSum += (cell->Gr_avg + cell->Gb_avg) / 2 * currentYGain;\n> + blueSum += cell->B_avg * currentYGain;\n> + }\n> + }\n> +\n> + /*\n> + * Estimate the sum of the brightness values, weighted with the gains\n> + * applied on the channels in AWB as the Rec. 601 luma.\n> + */\n> + double Y_sum = redSum * frameContext.awb.gains.red * .299 +\n> + greenSum * frameContext.awb.gains.green * .587 +\n> + blueSum * frameContext.awb.gains.blue * .114;\n> +\n> + /* Return the normalized relative luminance. */\n> + return Y_sum / (grid.height * grid.width) / kMaxLuminance;\n> +}\n> +\n> +\n> /**\n> * \\brief Process IPU3 statistics, and run AGC operations\n> * \\param[in] context The shared IPA context\n> @@ -267,7 +336,35 @@ void Agc::process(IPAContext &context, const ipu3_uapi_stats_3a *stats)\n> uint32_t &exposure = context.frameContext.agc.exposure;\n> double &analogueGain = context.frameContext.agc.gain;\n> measureBrightness(stats, context.configuration.grid.bdsGrid);\n> - computeExposure(exposure, analogueGain);\n> +\n> + double currentYGain = 1.0;\n> + /*\n> + * Normalized luma value target.\n> + *\n> + * It's a number that's chosen so that, when the camera points at a grey\n> + * target, the resulting image brightness is considered right.\n\nI think I'd change s/considered right/considered correct/ - but it's not\ncritical.\n\n> + */\n> + double targetY = 0.16;\n\nWow - this is a big change from the 60 that it was before. Did something\nfundamental happen?\n\nWill this be required to come from some sensor tuning profile at a later\ndate?\n\nIf so - I'd add a \n\t\\todo targetY should be calibrated by sensor tuning\n\n(Same for any other constant that has been manually tuned at present).\n\nIs targetY ever changed in the code? If not - perhaps it should be a\nconstexpr to show that it isn't modified.\n\nBut aside from those which are all minor.\n\n\nReviewed-by: Kieran Bingham \n\n> +\n> + /*\n> + * Do this calculation a few times as brightness increase can be\n> + * non-linear when there are saturated regions.\n> + */\n> + for (int i = 0; i < 8; i++) {\n> + double initialY = computeInitialY(context.frameContext,\n> + context.configuration.grid.bdsGrid,\n> + stats, currentYGain);\n> + double extra_gain = std::min(10.0, targetY / (initialY + .001));\n> +\n> + currentYGain *= extra_gain;\n> + LOG(IPU3Agc, Debug) << \"Initial Y \" << initialY\n> + << \" target \" << targetY\n> + << \" gives gain \" << currentYGain;\n> + if (extra_gain < 1.01)\n> + break;\n> + }\n> +\n> + computeExposure(exposure, analogueGain, currentYGain);\n> frameCount_++;\n> }\n> \n> diff --git a/src/ipa/ipu3/algorithms/agc.h b/src/ipa/ipu3/algorithms/agc.h\n> index 69e0b831..0a9152a9 100644\n> --- a/src/ipa/ipu3/algorithms/agc.h\n> +++ b/src/ipa/ipu3/algorithms/agc.h\n> @@ -34,7 +34,11 @@ private:\n> void measureBrightness(const ipu3_uapi_stats_3a *stats,\n> const ipu3_uapi_grid_config &grid);\n> void filterExposure();\n> - void computeExposure(uint32_t &exposure, double &gain);\n> + void computeExposure(uint32_t &exposure, double &gain, double currentYGain);\n> + double computeInitialY(IPAFrameContext &frameContext,\n> + const ipu3_uapi_grid_config &grid,\n> + const ipu3_uapi_stats_3a *stats,\n> + double currentYGain);\n> \n> uint64_t frameCount_;\n> uint64_t lastFrame_;\n> -- \n> 2.32.0\n>","headers":{"Return-Path":"","X-Original-To":"parsemail@patchwork.libcamera.org","Delivered-To":"parsemail@patchwork.libcamera.org","Received":["from lancelot.ideasonboard.com (lancelot.ideasonboard.com\n\t[92.243.16.209])\n\tby patchwork.libcamera.org (Postfix) with ESMTPS id 24DCABF415\n\tfor ;\n\tWed, 10 Nov 2021 22:29:22 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id 95D326034E;\n\tWed, 10 Nov 2021 23:29:21 +0100 (CET)","from perceval.ideasonboard.com (perceval.ideasonboard.com\n\t[IPv6:2001:4b98:dc2:55:216:3eff:fef7:d647])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id C54FA6033C\n\tfor ;\n\tWed, 10 Nov 2021 23:29:19 +0100 (CET)","from pendragon.ideasonboard.com\n\t(cpc89244-aztw30-2-0-cust3082.18-1.cable.virginm.net [86.31.172.11])\n\tby perceval.ideasonboard.com (Postfix) with ESMTPSA id 57CA98B6;\n\tWed, 10 Nov 2021 23:29:19 +0100 (CET)"],"Authentication-Results":"lancelot.ideasonboard.com; dkim=pass (1024-bit key;\n\tunprotected) header.d=ideasonboard.com header.i=@ideasonboard.com\n\theader.b=\"F2OHildY\"; dkim-atps=neutral","DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com;\n\ts=mail; t=1636583359;\n\tbh=Y/AoydYU5QaynTbk5Vy4Ysg2vGtCL1gsSEbZhJVmV80=;\n\th=In-Reply-To:References:Subject:From:To:Date:From;\n\tb=F2OHildYZAR4eiGvmITwQ7v+nikD/YzlESO2abOY7NvDfloYmdckhwtcBetKRiVJD\n\tx2RcUZqXKt3EPBOWF7NMSxJME4WFx1CatAxXk/1HTvbcLBD7CANksK0lf0tAcy1eG1\n\tEzrROXlhhsdtLymvRF4AKBc/yliw0OfOru60tdBU=","Content-Type":"text/plain; charset=\"utf-8\"","MIME-Version":"1.0","Content-Transfer-Encoding":"quoted-printable","In-Reply-To":"<20211110195901.85597-8-jeanmichel.hautbois@ideasonboard.com>","References":"<20211110195901.85597-1-jeanmichel.hautbois@ideasonboard.com>\n\t<20211110195901.85597-8-jeanmichel.hautbois@ideasonboard.com>","From":"Kieran Bingham ","To":"Jean-Michel Hautbois ,\n\tlibcamera-devel@lists.libcamera.org","Date":"Wed, 10 Nov 2021 22:29:16 +0000","Message-ID":"<163658335669.2121661.10867876860392000584@Monstersaurus>","User-Agent":"alot/0.10","Subject":"Re: [libcamera-devel] [PATCH v2 07/14] ipa: ipu3: agc: Improve gain\n\tcalculation","X-BeenThere":"libcamera-devel@lists.libcamera.org","X-Mailman-Version":"2.1.29","Precedence":"list","List-Id":"","List-Unsubscribe":",\n\t","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n\t","Errors-To":"libcamera-devel-bounces@lists.libcamera.org","Sender":"\"libcamera-devel\" "}},{"id":20839,"web_url":"https://patchwork.libcamera.org/comment/20839/","msgid":"<5c733b4e-f835-912f-a448-32a3876a1f1f@ideasonboard.com>","date":"2021-11-11T07:07:30","subject":"Re: [libcamera-devel] [PATCH v2 07/14] ipa: ipu3: agc: Improve gain\n\tcalculation","submitter":{"id":75,"url":"https://patchwork.libcamera.org/api/people/75/","name":"Jean-Michel Hautbois","email":"jeanmichel.hautbois@ideasonboard.com"},"content":"Hi Kieran,\n\nOn 10/11/2021 23:29, Kieran Bingham wrote:\n> Quoting Jean-Michel Hautbois (2021-11-10 19:58:54)\n>> When an image is partially saturated, its brightness is not increasing\n>> linearly when the shutter time or gain increases. It is a big issue with\n>> a backlight as the algorithm is fading to darkness right now.\n>>\n>> Introduce a function to estimate the brightness of the frame, based on\n>> the current exposure/gain and loop on it several times to estimate it\n>> again and approach the non linear function.\n>>\n>> Inspired-by: 7de5506c30b3 (\"libcamera: src: ipa: raspberrypi: agc: Improve gain update calculation for partly saturated images\")\n>> Signed-off-by: Jean-Michel Hautbois \n>> ---\n>> src/ipa/ipu3/algorithms/agc.cpp | 103 +++++++++++++++++++++++++++++++-\n>> src/ipa/ipu3/algorithms/agc.h | 6 +-\n>> 2 files changed, 105 insertions(+), 4 deletions(-)\n>>\n>> diff --git a/src/ipa/ipu3/algorithms/agc.cpp b/src/ipa/ipu3/algorithms/agc.cpp\n>> index 119a7938..ee37a9d5 100644\n>> --- a/src/ipa/ipu3/algorithms/agc.cpp\n>> +++ b/src/ipa/ipu3/algorithms/agc.cpp\n>> @@ -67,6 +67,9 @@ static constexpr uint32_t kMinCellsPerZoneRatio = 255 * 20 / 100;\n>> /* Number of frames to wait before calculating stats on minimum exposure */\n>> static constexpr uint32_t kNumStartupFrames = 10;\n>> \n>> +/* Maximum luminance used for brightness normalization */\n>> +static constexpr uint32_t kMaxLuminance = 255;\n>> +\n>> Agc::Agc()\n>> : frameCount_(0), iqMean_(0.0), lineDuration_(0s), minExposureLines_(0),\n>> maxExposureLines_(0), filteredExposure_(0s), currentExposure_(0s),\n>> @@ -186,10 +189,16 @@ void Agc::filterExposure()\n>> * \\brief Estimate the new exposure and gain values\n>> * \\param[inout] exposure The exposure value reference as a number of lines\n>> * \\param[inout] gain The gain reference to be updated\n>> + * \\param[in] currentYGain The gain calculated on the current brightness level\n>> */\n>> -void Agc::computeExposure(uint32_t &exposure, double &analogueGain)\n>> +void Agc::computeExposure(uint32_t &exposure, double &analogueGain, double currentYGain)\n>> {\n>> - /* Estimate the gain needed to have the proportion wanted */\n>> + /*\n>> + * Estimate the gain needed to have the proportion of pixels in a given\n>> + * range wanted. iqMean_ returns the mean value of the top 2% of the\n>> + * cumulative histogram, and we want it to be as close as possible to a\n>> + * configured target.\n>> + */\n>> double evGain = kEvGainTarget * knumHistogramBins / iqMean_;\n>> \n>> if (std::abs(evGain - 1.0) < 0.01) {\n>> @@ -199,6 +208,7 @@ void Agc::computeExposure(uint32_t &exposure, double &analogueGain)\n>> }\n>> \n>> /* extracted from Rpi::Agc::computeTargetExposure */\n>> +\n>> /* Calculate the shutter time in seconds */\n>> utils::Duration currentShutter = exposure * lineDuration_;\n>> LOG(IPU3Agc, Debug) << \"Actual total exposure \" << currentShutter * analogueGain\n>> @@ -206,6 +216,14 @@ void Agc::computeExposure(uint32_t &exposure, double &analogueGain)\n>> << \" Gain \" << analogueGain\n>> << \" Needed ev gain \" << evGain;\n>> \n>> + if (evGain < currentYGain)\n>> + evGain = currentYGain;\n>> +\n>> + /* Consider within 1% of the target as correctly exposed */\n>> + if (std::abs(evGain - 1.0) < 0.01)\n>> + LOG(IPU3Agc, Debug) << \"We are well exposed (iqMean = \"\n>> + << iqMean_ << \")\";\n>> +\n>> /*\n>> * Calculate the current exposure value for the scene as the latest\n>> * exposure value applied multiplied by the new estimated gain.\n>> @@ -253,6 +271,57 @@ void Agc::computeExposure(uint32_t &exposure, double &analogueGain)\n>> prevExposureValue_ = shutterTime * analogueGain;\n>> }\n>> \n>> +/**\n>> + * \\brief Estimate the average brightness of the frame\n>> + * \\param[in] context The shared IPA context\n> \n> frameContext?\n> \n>> + * \\param[in] grid The grid used to store the statistics in the IPU3\n>> + * \\param[in] stats The IPU3 statistics and ISP results\n>> + * \\param[in] currentYGain The gain calculated on the current brightness level\n>> + * \\return The normalized luma\n>> + *\n>> + * Luma is the weighted sum of gamma-compressed R′G′B′ components of a color\n>> + * video. The luma values are normalized as 0.0 to 1.0, with 1.0 being a\n>> + * theoretical perfect reflector of 100% reference white. We use the Rec. 601\n>> + * luma here.\n>> + *\n>> + * More detailed information can be found in:\n>> + * https://en.wikipedia.org/wiki/Luma_(video)\n> \n> Thank you - that all helps a lot in making it understandable (and being\n> explicit about where these conversions are from/represent).\n> \n> \n>> + */\n>> +double Agc::computeInitialY(IPAFrameContext &frameContext,\n>> + const ipu3_uapi_grid_config &grid,\n>> + const ipu3_uapi_stats_3a *stats,\n>> + double currentYGain)\n>> +{\n>> + double redSum = 0, greenSum = 0, blueSum = 0;\n>> +\n>> + for (unsigned int cellY = 0; cellY < grid.height; cellY++) {\n>> + for (unsigned int cellX = 0; cellX < grid.width; cellX++) {\n>> + uint32_t cellPosition = cellY * stride_ + cellX;\n>> +\n>> + const ipu3_uapi_awb_set_item *cell =\n>> + reinterpret_cast(\n>> + &stats->awb_raw_buffer.meta_data[cellPosition]\n>> + );\n>> +\n>> + redSum += cell->R_avg * currentYGain;\n>> + greenSum += (cell->Gr_avg + cell->Gb_avg) / 2 * currentYGain;\n>> + blueSum += cell->B_avg * currentYGain;\n>> + }\n>> + }\n>> +\n>> + /*\n>> + * Estimate the sum of the brightness values, weighted with the gains\n>> + * applied on the channels in AWB as the Rec. 601 luma.\n>> + */\n>> + double Y_sum = redSum * frameContext.awb.gains.red * .299 +\n>> + greenSum * frameContext.awb.gains.green * .587 +\n>> + blueSum * frameContext.awb.gains.blue * .114;\n>> +\n>> + /* Return the normalized relative luminance. */\n>> + return Y_sum / (grid.height * grid.width) / kMaxLuminance;\n>> +}\n>> +\n>> +\n>> /**\n>> * \\brief Process IPU3 statistics, and run AGC operations\n>> * \\param[in] context The shared IPA context\n>> @@ -267,7 +336,35 @@ void Agc::process(IPAContext &context, const ipu3_uapi_stats_3a *stats)\n>> uint32_t &exposure = context.frameContext.agc.exposure;\n>> double &analogueGain = context.frameContext.agc.gain;\n>> measureBrightness(stats, context.configuration.grid.bdsGrid);\n>> - computeExposure(exposure, analogueGain);\n>> +\n>> + double currentYGain = 1.0;\n>> + /*\n>> + * Normalized luma value target.\n>> + *\n>> + * It's a number that's chosen so that, when the camera points at a grey\n>> + * target, the resulting image brightness is considered right.\n> \n> I think I'd change s/considered right/considered correct/ - but it's not\n> critical.\n> \n>> + */\n>> + double targetY = 0.16;\n> \n> Wow - this is a big change from the 60 that it was before. Did something\n> fundamental happen?\n\nI am now returning the normalized luma from computeInitialY() which is \nbasically dividing it by 255. This is the same as setting targetY = 41 \nwithout the division, and this is the value used in RPi too. I have seen \none or two cases where the targetY=60 (so, ~0.25) was a bit high.\n\n> \n> Will this be required to come from some sensor tuning profile at a later\n> date?\n> \n> If so - I'd add a\n> \t\\todo targetY should be calibrated by sensor tuning\n> \n> (Same for any other constant that has been manually tuned at present).\n> \n> Is targetY ever changed in the code? If not - perhaps it should be a\n> constexpr to show that it isn't modified.\n> \n> But aside from those which are all minor.\n\nIt could be configured, it can certainly be a constexpr :-).\nShould the maximum number of loops be a constexpr too ?\n\n> \n> \n> Reviewed-by: Kieran Bingham \n> \n>> +\n>> + /*\n>> + * Do this calculation a few times as brightness increase can be\n>> + * non-linear when there are saturated regions.\n>> + */\n>> + for (int i = 0; i < 8; i++) {\n>> + double initialY = computeInitialY(context.frameContext,\n>> + context.configuration.grid.bdsGrid,\n>> + stats, currentYGain);\n>> + double extra_gain = std::min(10.0, targetY / (initialY + .001));\n>> +\n>> + currentYGain *= extra_gain;\n>> + LOG(IPU3Agc, Debug) << \"Initial Y \" << initialY\n>> + << \" target \" << targetY\n>> + << \" gives gain \" << currentYGain;\n>> + if (extra_gain < 1.01)\n>> + break;\n>> + }\n>> +\n>> + computeExposure(exposure, analogueGain, currentYGain);\n>> frameCount_++;\n>> }\n>> \n>> diff --git a/src/ipa/ipu3/algorithms/agc.h b/src/ipa/ipu3/algorithms/agc.h\n>> index 69e0b831..0a9152a9 100644\n>> --- a/src/ipa/ipu3/algorithms/agc.h\n>> +++ b/src/ipa/ipu3/algorithms/agc.h\n>> @@ -34,7 +34,11 @@ private:\n>> void measureBrightness(const ipu3_uapi_stats_3a *stats,\n>> const ipu3_uapi_grid_config &grid);\n>> void filterExposure();\n>> - void computeExposure(uint32_t &exposure, double &gain);\n>> + void computeExposure(uint32_t &exposure, double &gain, double currentYGain);\n>> + double computeInitialY(IPAFrameContext &frameContext,\n>> + const ipu3_uapi_grid_config &grid,\n>> + const ipu3_uapi_stats_3a *stats,\n>> + double currentYGain);\n>> \n>> uint64_t frameCount_;\n>> uint64_t lastFrame_;\n>> -- \n>> 2.32.0\n>>","headers":{"Return-Path":"","X-Original-To":"parsemail@patchwork.libcamera.org","Delivered-To":"parsemail@patchwork.libcamera.org","Received":["from lancelot.ideasonboard.com (lancelot.ideasonboard.com\n\t[92.243.16.209])\n\tby patchwork.libcamera.org (Postfix) with ESMTPS id 04A33BF415\n\tfor ;\n\tThu, 11 Nov 2021 07:07:36 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id F29156035A;\n\tThu, 11 Nov 2021 08:07:34 +0100 (CET)","from perceval.ideasonboard.com (perceval.ideasonboard.com\n\t[IPv6:2001:4b98:dc2:55:216:3eff:fef7:d647])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id EEDDB600BF\n\tfor ;\n\tThu, 11 Nov 2021 08:07:33 +0100 (CET)","from [IPV6:2a01:e0a:169:7140:e627:8337:a781:d98] (unknown\n\t[IPv6:2a01:e0a:169:7140:e627:8337:a781:d98])\n\tby perceval.ideasonboard.com (Postfix) with ESMTPSA id 9D8E5E51;\n\tThu, 11 Nov 2021 08:07:33 +0100 (CET)"],"Authentication-Results":"lancelot.ideasonboard.com; dkim=pass (1024-bit key;\n\tunprotected) header.d=ideasonboard.com header.i=@ideasonboard.com\n\theader.b=\"N+9wGt5Z\"; dkim-atps=neutral","DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com;\n\ts=mail; t=1636614453;\n\tbh=H3K/CQIloITya2aW4vGD6WKVfm7e9SoPshYQO0kQBns=;\n\th=Date:Subject:To:References:From:In-Reply-To:From;\n\tb=N+9wGt5ZcBJ8m+jYIptDHAv3pUQAYk+gEq4XFOJ8KyQfyTEqsIOOpXJ8kGmcgrn+z\n\tq0XWToa6XxcWjIN9D+BVgagFEdu1wnY7E9OY3zD07tEUaN+ch64MX81q+RVQmY6yAx\n\tNYsGmRBdeZycqw1eui5PIYPOGkIIzGqqz784Nj2c=","Message-ID":"<5c733b4e-f835-912f-a448-32a3876a1f1f@ideasonboard.com>","Date":"Thu, 11 Nov 2021 08:07:30 +0100","MIME-Version":"1.0","User-Agent":"Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101\n\tThunderbird/91.2.1","Content-Language":"en-US","To":"Kieran Bingham ,\n\tlibcamera-devel@lists.libcamera.org","References":"<20211110195901.85597-1-jeanmichel.hautbois@ideasonboard.com>\n\t<20211110195901.85597-8-jeanmichel.hautbois@ideasonboard.com>\n\t<163658335669.2121661.10867876860392000584@Monstersaurus>","From":"Jean-Michel Hautbois ","In-Reply-To":"<163658335669.2121661.10867876860392000584@Monstersaurus>","Content-Type":"text/plain; charset=UTF-8; format=flowed","Content-Transfer-Encoding":"8bit","Subject":"Re: [libcamera-devel] [PATCH v2 07/14] ipa: ipu3: agc: Improve gain\n\tcalculation","X-BeenThere":"libcamera-devel@lists.libcamera.org","X-Mailman-Version":"2.1.29","Precedence":"list","List-Id":"","List-Unsubscribe":",\n\t","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n\t","Errors-To":"libcamera-devel-bounces@lists.libcamera.org","Sender":"\"libcamera-devel\" "}}]