[{"id":36358,"web_url":"https://patchwork.libcamera.org/comment/36358/","msgid":"<176095520201.336133.2889016243009646600@localhost>","date":"2025-10-20T10:13:22","subject":"Re: [PATCH 5/5] ipa: rpi: lux: Use floating statistics region to\n\tobtain the current Y value","submitter":{"id":184,"url":"https://patchwork.libcamera.org/api/people/184/","name":"Stefan Klug","email":"stefan.klug@ideasonboard.com"},"content":"Hi David,\n\nQuoting David Plowman (2025-10-17 12:05:41)\n> The Y value from the first floating region is now a better choice for\n> a Y value that is invariant to (for example) the metering mode.\n> \n> Both VC4 and PiSP platforms store full image Y statistics here.\n> \n> Signed-off-by: David Plowman \n\nLooks good to me.\n\nReviewed-by: Stefan Klug \n\nCheers,\nStefan\n\n> ---\n> src/ipa/rpi/controller/rpi/lux.cpp | 11 +++++++++--\n> 1 file changed, 9 insertions(+), 2 deletions(-)\n> \n> diff --git a/src/ipa/rpi/controller/rpi/lux.cpp b/src/ipa/rpi/controller/rpi/lux.cpp\n> index acaa6e57..7dab27cc 100644\n> --- a/src/ipa/rpi/controller/rpi/lux.cpp\n> +++ b/src/ipa/rpi/controller/rpi/lux.cpp\n> @@ -85,14 +85,21 @@ void Lux::process(StatisticsPtr &stats, Metadata *imageMetadata)\n> {\n> DeviceStatus deviceStatus;\n> if (imageMetadata->get(\"device.status\", deviceStatus) == 0) {\n> + /*\n> + * We've set up the first floating AGC region to collect full image stats. This\n> + * is a better choice than the Y-histogram, for example, because it's invariant\n> + * to the metering mode (and cheaper to evaluate).\n> + */\n> + auto const &fullImageStats = stats->agcRegions.getFloating(0);\n> + double currentY = static_cast(fullImageStats.val.ySum) / fullImageStats.counted;\n> +\n> double currentGain = deviceStatus.analogueGain;\n> double currentAperture = deviceStatus.aperture.value_or(currentAperture_);\n> - double currentY = stats->yHist.interQuantileMean(0, 1);\n> double gainRatio = referenceGain_ / currentGain;\n> double exposureTimeRatio =\n> referenceExposureTime_ / deviceStatus.exposureTime;\n> double apertureRatio = referenceAperture_ / currentAperture;\n> - double yRatio = currentY * (65536 / stats->yHist.bins()) / referenceY_;\n> + double yRatio = currentY / referenceY_;\n> double estimatedLux = exposureTimeRatio * gainRatio *\n> apertureRatio * apertureRatio *\n> yRatio * referenceLux_ / sensitivity_;\n> -- \n> 2.47.3\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 42ACBC3259\n\tfor ;\n\tMon, 20 Oct 2025 10:13:27 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id 639E960713;\n\tMon, 20 Oct 2025 12:13:26 +0200 (CEST)","from perceval.ideasonboard.com (perceval.ideasonboard.com\n\t[213.167.242.64])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 179CF60706\n\tfor ;\n\tMon, 20 Oct 2025 12:13:25 +0200 (CEST)","from ideasonboard.com (unknown\n\t[IPv6:2a00:6020:448c:6c00:9f50:5b33:d3ec:e1ea])\n\tby perceval.ideasonboard.com (Postfix) with UTF8SMTPSA id 3D239F52;\n\tMon, 20 Oct 2025 12:11:42 +0200 (CEST)"],"Authentication-Results":"lancelot.ideasonboard.com; dkim=pass (1024-bit key;\n\tunprotected) header.d=ideasonboard.com header.i=@ideasonboard.com\n\theader.b=\"ZVdfLXhI\"; dkim-atps=neutral","DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com;\n\ts=mail; t=1760955102;\n\tbh=UmOFibJYXOS0uLNtltTjMoI2Wgy9F+wHF2AOLJPYjbU=;\n\th=In-Reply-To:References:Subject:From:Cc:To:Date:From;\n\tb=ZVdfLXhI6fINk6wnoAZWXeynvEvsxtpj+anPE9F3H5UqutPXTTEjM3C0R4uCvUljS\n\tUYaIQ/rb6arE72lPFW1hiWVIyLA2YtmJzxy2DrSU1sz9XwBD6VGHpETR+s2pFJptVA\n\tU9J3X6yQwWaSFYI3bVeRJLfea9Fp0JFNxln/ngTo=","Content-Type":"text/plain; charset=\"utf-8\"","MIME-Version":"1.0","Content-Transfer-Encoding":"quoted-printable","In-Reply-To":"<20251017102704.3887-6-david.plowman@raspberrypi.com>","References":"<20251017102704.3887-1-david.plowman@raspberrypi.com>\n\t<20251017102704.3887-6-david.plowman@raspberrypi.com>","Subject":"Re: [PATCH 5/5] ipa: rpi: lux: Use floating statistics region to\n\tobtain the current Y value","From":"Stefan Klug ","Cc":"David Plowman ","To":"David Plowman ,\n\tlibcamera-devel@lists.libcamera.org","Date":"Mon, 20 Oct 2025 12:13:22 +0200","Message-ID":"<176095520201.336133.2889016243009646600@localhost>","User-Agent":"alot/0.12.dev8+g2c003385c862.d20250602","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":36398,"web_url":"https://patchwork.libcamera.org/comment/36398/","msgid":"","date":"2025-10-23T07:40:36","subject":"Re: [PATCH 5/5] ipa: rpi: lux: Use floating statistics region to\n\tobtain the current Y value","submitter":{"id":34,"url":"https://patchwork.libcamera.org/api/people/34/","name":"Naushir Patuck","email":"naush@raspberrypi.com"},"content":"Hi David,\n\n\nOn Fri, 17 Oct 2025 at 11:27, David Plowman \nwrote:\n\n> The Y value from the first floating region is now a better choice for\n> a Y value that is invariant to (for example) the metering mode.\n>\n> Both VC4 and PiSP platforms store full image Y statistics here.\n>\n> Signed-off-by: David Plowman \n>\n\nReviewed-by: Naushir Patuck \n\n\n> ---\n> src/ipa/rpi/controller/rpi/lux.cpp | 11 +++++++++--\n> 1 file changed, 9 insertions(+), 2 deletions(-)\n>\n> diff --git a/src/ipa/rpi/controller/rpi/lux.cpp\n> b/src/ipa/rpi/controller/rpi/lux.cpp\n> index acaa6e57..7dab27cc 100644\n> --- a/src/ipa/rpi/controller/rpi/lux.cpp\n> +++ b/src/ipa/rpi/controller/rpi/lux.cpp\n> @@ -85,14 +85,21 @@ void Lux::process(StatisticsPtr &stats, Metadata\n> *imageMetadata)\n> {\n> DeviceStatus deviceStatus;\n> if (imageMetadata->get(\"device.status\", deviceStatus) == 0) {\n> + /*\n> + * We've set up the first floating AGC region to collect\n> full image stats. This\n> + * is a better choice than the Y-histogram, for example,\n> because it's invariant\n> + * to the metering mode (and cheaper to evaluate).\n> + */\n> + auto const &fullImageStats =\n> stats->agcRegions.getFloating(0);\n> + double currentY =\n> static_cast(fullImageStats.val.ySum) / fullImageStats.counted;\n> +\n> double currentGain = deviceStatus.analogueGain;\n> double currentAperture =\n> deviceStatus.aperture.value_or(currentAperture_);\n> - double currentY = stats->yHist.interQuantileMean(0, 1);\n> double gainRatio = referenceGain_ / currentGain;\n> double exposureTimeRatio =\n> referenceExposureTime_ / deviceStatus.exposureTime;\n> double apertureRatio = referenceAperture_ /\n> currentAperture;\n> - double yRatio = currentY * (65536 / stats->yHist.bins()) /\n> referenceY_;\n> + double yRatio = currentY / referenceY_;\n> double estimatedLux = exposureTimeRatio * gainRatio *\n> apertureRatio * apertureRatio *\n> yRatio * referenceLux_ /\n> sensitivity_;\n> --\n> 2.47.3\n>\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 25B44BE080\n\tfor ;\n\tThu, 23 Oct 2025 07:41:16 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id 41C78607AE;\n\tThu, 23 Oct 2025 09:41:15 +0200 (CEST)","from mail-vs1-xe32.google.com (mail-vs1-xe32.google.com\n\t[IPv6:2607:f8b0:4864:20::e32])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id CA5F5607A6\n\tfor ;\n\tThu, 23 Oct 2025 09:41:13 +0200 (CEST)","by mail-vs1-xe32.google.com with SMTP id\n\tada2fe7eead31-5db1b920a3aso34561137.3\n\tfor ;\n\tThu, 23 Oct 2025 00:41:13 -0700 (PDT)"],"Authentication-Results":"lancelot.ideasonboard.com; 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