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{
    "id": 23081,
    "url": "https://patchwork.libcamera.org/api/patches/23081/?format=api",
    "web_url": "https://patchwork.libcamera.org/patch/23081/",
    "project": {
        "id": 1,
        "url": "https://patchwork.libcamera.org/api/projects/1/?format=api",
        "name": "libcamera",
        "link_name": "libcamera",
        "list_id": "libcamera_core",
        "list_email": "libcamera-devel@lists.libcamera.org",
        "web_url": "",
        "scm_url": "",
        "webscm_url": ""
    },
    "msgid": "<20250331144352.736700-9-stefan.klug@ideasonboard.com>",
    "date": "2025-03-31T14:43:47",
    "name": "[8/9] libipa: agc_mean_luminance: Add exposure compensation support",
    "commit_ref": null,
    "pull_url": null,
    "state": "superseded",
    "archived": false,
    "hash": "a0343f76746b6c6e2cdb3e433cde6a6f73e2baa2",
    "submitter": {
        "id": 184,
        "url": "https://patchwork.libcamera.org/api/people/184/?format=api",
        "name": "Stefan Klug",
        "email": "stefan.klug@ideasonboard.com"
    },
    "delegate": null,
    "mbox": "https://patchwork.libcamera.org/patch/23081/mbox/",
    "series": [
        {
            "id": 5094,
            "url": "https://patchwork.libcamera.org/api/series/5094/?format=api",
            "web_url": "https://patchwork.libcamera.org/project/libcamera/list/?series=5094",
            "date": "2025-03-31T14:43:39",
            "name": "Wdr preparations",
            "version": 1,
            "mbox": "https://patchwork.libcamera.org/series/5094/mbox/"
        }
    ],
    "comments": "https://patchwork.libcamera.org/api/patches/23081/comments/",
    "check": "pending",
    "checks": "https://patchwork.libcamera.org/api/patches/23081/checks/",
    "tags": {},
    "headers": {
        "Return-Path": "<libcamera-devel-bounces@lists.libcamera.org>",
        "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 E53DBC3213\n\tfor <parsemail@patchwork.libcamera.org>;\n\tMon, 31 Mar 2025 14:44:21 +0000 (UTC)",
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        ],
        "Authentication-Results": "lancelot.ideasonboard.com; dkim=pass (1024-bit key;\n\tunprotected) header.d=ideasonboard.com header.i=@ideasonboard.com\n\theader.b=\"iWDG6bJe\"; dkim-atps=neutral",
        "DKIM-Signature": "v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com;\n\ts=mail; t=1743432147;\n\tbh=DsaJdPyfZNhM1/5qcUZRWzLV3yYzuSEh2tyccCDzu7s=;\n\th=From:To:Cc:Subject:Date:In-Reply-To:References:From;\n\tb=iWDG6bJeyRAI+YpnwQrKwe906oNOcsEp3nu2wwxUYnh6AbDJCy5ODNjvtk5RLmKE5\n\tGA56hfZhqYdsKcC9aIjrcyq5//jMnEUezFvt0QCx4pU6UhYCX3NprfiJwKbemLgsei\n\tKxRMtsDAQHENTxRZ8a9b3S7D9W+0zSv8hG+IppJU=",
        "From": "Stefan Klug <stefan.klug@ideasonboard.com>",
        "To": "libcamera-devel@lists.libcamera.org",
        "Cc": "Stefan Klug <stefan.klug@ideasonboard.com>",
        "Subject": "[PATCH 8/9] libipa: agc_mean_luminance: Add exposure compensation\n\tsupport",
        "Date": "Mon, 31 Mar 2025 16:43:47 +0200",
        "Message-ID": "<20250331144352.736700-9-stefan.klug@ideasonboard.com>",
        "X-Mailer": "git-send-email 2.43.0",
        "In-Reply-To": "<20250331144352.736700-1-stefan.klug@ideasonboard.com>",
        "References": "<20250331144352.736700-1-stefan.klug@ideasonboard.com>",
        "MIME-Version": "1.0",
        "Content-Transfer-Encoding": "8bit",
        "X-BeenThere": "libcamera-devel@lists.libcamera.org",
        "X-Mailman-Version": "2.1.29",
        "Precedence": "list",
        "List-Id": "<libcamera-devel.lists.libcamera.org>",
        "List-Unsubscribe": "<https://lists.libcamera.org/options/libcamera-devel>,\n\t<mailto:libcamera-devel-request@lists.libcamera.org?subject=unsubscribe>",
        "List-Archive": "<https://lists.libcamera.org/pipermail/libcamera-devel/>",
        "List-Post": "<mailto:libcamera-devel@lists.libcamera.org>",
        "List-Help": "<mailto:libcamera-devel-request@lists.libcamera.org?subject=help>",
        "List-Subscribe": "<https://lists.libcamera.org/listinfo/libcamera-devel>,\n\t<mailto:libcamera-devel-request@lists.libcamera.org?subject=subscribe>",
        "Errors-To": "libcamera-devel-bounces@lists.libcamera.org",
        "Sender": "\"libcamera-devel\" <libcamera-devel-bounces@lists.libcamera.org>"
    },
    "content": "Exposure compensation allows to over- or under-expose an\nimage by a given value (typically provided in EV). Add support\nfor that in agc_mean_luminance.\n\nSigned-off-by: Stefan Klug <stefan.klug@ideasonboard.com>\n---\n src/ipa/libipa/agc_mean_luminance.cpp | 23 +++++++++++++++++++++--\n src/ipa/libipa/agc_mean_luminance.h   |  6 ++++++\n 2 files changed, 27 insertions(+), 2 deletions(-)",
    "diff": "diff --git a/src/ipa/libipa/agc_mean_luminance.cpp b/src/ipa/libipa/agc_mean_luminance.cpp\nindex 9154f083a510..a498b646bdd5 100644\n--- a/src/ipa/libipa/agc_mean_luminance.cpp\n+++ b/src/ipa/libipa/agc_mean_luminance.cpp\n@@ -44,6 +44,15 @@ static constexpr uint32_t kNumStartupFrames = 10;\n  */\n static constexpr double kDefaultRelativeLuminanceTarget = 0.16;\n \n+/*\n+ * Maximum relative luminance target\n+ *\n+ * This value limits the relative luminance target after applying the exposure\n+ * compensation. Targeting a value above this limit results in saturation\n+ * and the inability to regulate properly.\n+ */\n+static constexpr double kMaxRelativeLuminanceTarget = 0.95;\n+\n /**\n  * \\struct AgcMeanLuminance::AgcConstraint\n  * \\brief The boundaries and target for an AeConstraintMode constraint\n@@ -134,7 +143,7 @@ static constexpr double kDefaultRelativeLuminanceTarget = 0.16;\n  */\n \n AgcMeanLuminance::AgcMeanLuminance()\n-\t: frameCount_(0), filteredExposure_(0s), relativeLuminanceTarget_(0)\n+\t: frameCount_(0), filteredExposure_(0s), relativeLuminanceTarget_(0), exposureCompensation_(1.0)\n {\n }\n \n@@ -369,6 +378,15 @@ int AgcMeanLuminance::parseTuningData(const YamlObject &tuningData)\n \treturn parseExposureModes(tuningData);\n }\n \n+/**\n+ * \\fn AgcMeanLuminance::setExposureCompensation()\n+ * \\brief Set the exposure compensation value\n+ * \\param[in] gain The exposure compensation gain\n+ *\n+ * This function sets the exposure compensation value to be used in the\n+ * AGC calculations. It is expressed as gain instead of EV.\n+ */\n+\n /**\n  * \\brief Set the ExposureModeHelper limits for this class\n  * \\param[in] minExposureTime Minimum exposure time to allow\n@@ -425,7 +443,8 @@ void AgcMeanLuminance::setLimits(utils::Duration minExposureTime,\n  */\n double AgcMeanLuminance::estimateInitialGain() const\n {\n-\tdouble yTarget = relativeLuminanceTarget_;\n+\tdouble yTarget = std::min(relativeLuminanceTarget_ * exposureCompensation_,\n+\t\t\t\t  kMaxRelativeLuminanceTarget);\n \tdouble yGain = 1.0;\n \n \t/*\ndiff --git a/src/ipa/libipa/agc_mean_luminance.h b/src/ipa/libipa/agc_mean_luminance.h\nindex c41391cb0b73..cad7ef845487 100644\n--- a/src/ipa/libipa/agc_mean_luminance.h\n+++ b/src/ipa/libipa/agc_mean_luminance.h\n@@ -44,6 +44,11 @@ public:\n \n \tint parseTuningData(const YamlObject &tuningData);\n \n+\tvoid setExposureCompensation(double gain)\n+\t{\n+\t\texposureCompensation_ = gain;\n+\t}\n+\n \tvoid setLimits(utils::Duration minExposureTime, utils::Duration maxExposureTime,\n \t\t       double minGain, double maxGain);\n \n@@ -84,6 +89,7 @@ private:\n \t\t\t\t   double gain);\n \tutils::Duration filterExposure(utils::Duration exposureValue);\n \n+\tdouble exposureCompensation_;\n \tuint64_t frameCount_;\n \tutils::Duration filteredExposure_;\n \tdouble relativeLuminanceTarget_;\n",
    "prefixes": [
        "8/9"
    ]
}