{"id":24412,"url":"https://patchwork.libcamera.org/api/patches/24412/?format=json","web_url":"https://patchwork.libcamera.org/patch/24412/","project":{"id":1,"url":"https://patchwork.libcamera.org/api/projects/1/?format=json","name":"libcamera","link_name":"libcamera","list_id":"libcamera_core","list_email":"libcamera-devel@lists.libcamera.org","web_url":"","scm_url":"","webscm_url":""},"msgid":"<20250919094041.183031-4-stefan.klug@ideasonboard.com>","date":"2025-09-19T09:40:18","name":"[v5,03/19] libipa: camera_sensor_helper: Add quantizeGain() function","commit_ref":"1400058ed447867415c73d905d2c0cb9fef9a551","pull_url":null,"state":"accepted","archived":false,"hash":"2a7ac15260e258c098504a0ca409d87d276be81d","submitter":{"id":184,"url":"https://patchwork.libcamera.org/api/people/184/?format=json","name":"Stefan Klug","email":"stefan.klug@ideasonboard.com"},"delegate":null,"mbox":"https://patchwork.libcamera.org/patch/24412/mbox/","series":[{"id":5450,"url":"https://patchwork.libcamera.org/api/series/5450/?format=json","web_url":"https://patchwork.libcamera.org/project/libcamera/list/?series=5450","date":"2025-09-19T09:40:15","name":"Implement WDR algorithm","version":5,"mbox":"https://patchwork.libcamera.org/series/5450/mbox/"}],"comments":"https://patchwork.libcamera.org/api/patches/24412/comments/","check":"pending","checks":"https://patchwork.libcamera.org/api/patches/24412/checks/","tags":{},"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 BDF5BC328C\n\tfor ;\n\tFri, 19 Sep 2025 09:41:06 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id 266D96B5A5;\n\tFri, 19 Sep 2025 11:41:06 +0200 (CEST)","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 706B86B5A0\n\tfor ;\n\tFri, 19 Sep 2025 11:41:02 +0200 (CEST)","from ideasonboard.com (unknown\n\t[IPv6:2a00:6020:448c:6c00:4d54:eab8:98ca:163b])\n\tby perceval.ideasonboard.com (Postfix) with UTF8SMTPSA id 3065F7E4;\n\tFri, 19 Sep 2025 11:39:42 +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=\"PzVbY2+N\"; dkim-atps=neutral","DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com;\n\ts=mail; t=1758274782;\n\tbh=utyQW5ybO12a+eoYtHAe559BLHxWYaUugkp+e1Mar/Q=;\n\th=From:To:Cc:Subject:Date:In-Reply-To:References:From;\n\tb=PzVbY2+NCq9CL4pRELgXQesDd5bGh1Je9asem0bbakQ+PcKxZmpg17JnLw+nQMdg3\n\tBCRhgiafR4DfC0Zp3ujWYIH5bVDiHGdNWRIUj+tPIaGFsoja1MaoXpTw5WXfCnkCIY\n\tl0BaoX85KR2iAUmGHHHno0dZDdM3Xgk0AovIklP0=","From":"Stefan Klug ","To":"libcamera-devel@lists.libcamera.org","Cc":"Stefan Klug ,\n\tIsaac Scott ,\n\tDaniel Scally ","Subject":"[PATCH v5 03/19] libipa: camera_sensor_helper: Add quantizeGain()\n\tfunction","Date":"Fri, 19 Sep 2025 11:40:18 +0200","Message-ID":"<20250919094041.183031-4-stefan.klug@ideasonboard.com>","X-Mailer":"git-send-email 2.48.1","In-Reply-To":"<20250919094041.183031-1-stefan.klug@ideasonboard.com>","References":"<20250919094041.183031-1-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":"","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\" "},"content":"Add a small utility function that calculates the quantized gain that\ngets applied by a sensor when the gain code is set to gainCode(gain).\nThis is needed by algorithms to calculate a digital correction gain that\ngets applied to mitigate the error introduce by quantization.\n\nSigned-off-by: Stefan Klug \nReviewed-by: Isaac Scott \nReviewed-by: Daniel Scally \n\n---\n\nChanges in v3:\n- Remove virtual from quantizeGain()\n- Improved documentation\n- Collected tags\n---\n src/ipa/libipa/camera_sensor_helper.cpp | 23 +++++++++++++++++++++++\n src/ipa/libipa/camera_sensor_helper.h | 1 +\n 2 files changed, 24 insertions(+)","diff":"diff --git a/src/ipa/libipa/camera_sensor_helper.cpp b/src/ipa/libipa/camera_sensor_helper.cpp\nindex dcd69d9f2bbb..01f6470a196f 100644\n--- a/src/ipa/libipa/camera_sensor_helper.cpp\n+++ b/src/ipa/libipa/camera_sensor_helper.cpp\n@@ -131,6 +131,29 @@ double CameraSensorHelper::gain(uint32_t gainCode) const\n \t}\n }\n \n+/**\n+ * \\brief Quantize the given gain value\n+ * \\param[in] _gain The real gain\n+ * \\param[out] quantizationGain The gain that is lost due to quantization\n+ *\n+ * This function returns the actual gain that is applied when the sensor's gain\n+ * is set to gainCode(_gain).\n+ *\n+ * It shall be guaranteed that gainCode(_gain) == gainCode(quantizeGain(_gain)).\n+ *\n+ * If \\a quantizationGain is provided it is populated with the gain that must be\n+ * applied on top to correct for the losses due to quantization.\n+ *\n+ * \\return The quantized real gain\n+ */\n+double CameraSensorHelper::quantizeGain(double _gain, double *quantizationGain) const\n+{\n+\tdouble g = gain(gainCode(_gain));\n+\tif (quantizationGain)\n+\t\t*quantizationGain = _gain / g;\n+\treturn g;\n+}\n+\n /**\n * \\struct CameraSensorHelper::AnalogueGainLinear\n * \\brief Analogue gain constants for the linear gain model\ndiff --git a/src/ipa/libipa/camera_sensor_helper.h b/src/ipa/libipa/camera_sensor_helper.h\nindex a9300a64f1e7..bd3d0beec77f 100644\n--- a/src/ipa/libipa/camera_sensor_helper.h\n+++ b/src/ipa/libipa/camera_sensor_helper.h\n@@ -29,6 +29,7 @@ public:\n \tstd::optional blackLevel() const { return blackLevel_; }\n \tvirtual uint32_t gainCode(double gain) const;\n \tvirtual double gain(uint32_t gainCode) const;\n+\tdouble quantizeGain(double gain, double *quantizationGain) const;\n \n protected:\n \tstruct AnalogueGainLinear {\n","prefixes":["v5","03/19"]}