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{ "id": 14532, "url": "https://patchwork.libcamera.org/api/patches/14532/?format=api", "web_url": "https://patchwork.libcamera.org/patch/14532/", "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": "<20211110195901.85597-5-jeanmichel.hautbois@ideasonboard.com>", "date": "2021-11-10T19:58:51", "name": "[libcamera-devel,v2,04/14] ipa: ipu3: agc: Limit the number of saturated cells", "commit_ref": null, "pull_url": null, "state": "superseded", "archived": false, "hash": "9ae9e8c44f776fa9318d1050fc0aebc2b4b5bccd", "submitter": { "id": 75, "url": "https://patchwork.libcamera.org/api/people/75/?format=api", "name": "Jean-Michel Hautbois", "email": "jeanmichel.hautbois@ideasonboard.com" }, "delegate": null, "mbox": "https://patchwork.libcamera.org/patch/14532/mbox/", "series": [ { "id": 2708, "url": "https://patchwork.libcamera.org/api/series/2708/?format=api", "web_url": "https://patchwork.libcamera.org/project/libcamera/list/?series=2708", "date": "2021-11-10T19:58:47", "name": "IPA: IPU3: Introduce per-frame controls", "version": 2, "mbox": "https://patchwork.libcamera.org/series/2708/mbox/" } ], "comments": "https://patchwork.libcamera.org/api/patches/14532/comments/", "check": "pending", "checks": "https://patchwork.libcamera.org/api/patches/14532/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 4772EC324E\n\tfor <parsemail@patchwork.libcamera.org>;\n\tWed, 10 Nov 2021 19:59:15 +0000 (UTC)", "from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id 1159E603EE;\n\tWed, 10 Nov 2021 20:59:13 +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 DB8B66035F\n\tfor <libcamera-devel@lists.libcamera.org>;\n\tWed, 10 Nov 2021 20:59:06 +0100 (CET)", "from tatooine.ideasonboard.com (unknown\n\t[IPv6:2a01:e0a:169:7140:7713:3465:89e6:c5cd])\n\tby perceval.ideasonboard.com (Postfix) with ESMTPSA id 9089B11FB;\n\tWed, 10 Nov 2021 20:59:06 +0100 (CET)" ], "Authentication-Results": "lancelot.ideasonboard.com;\n\tdkim=fail reason=\"signature verification failed\" (1024-bit key;\n\tunprotected) header.d=ideasonboard.com header.i=@ideasonboard.com\n\theader.b=\"BiYAPtEL\"; dkim-atps=neutral", "DKIM-Signature": "v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com;\n\ts=mail; t=1636574346;\n\tbh=hyHcJcHG38gpe/ZG8HtCcRXH9TFLVLLWAH5nYGm6YGE=;\n\th=From:To:Cc:Subject:Date:In-Reply-To:References:From;\n\tb=BiYAPtELa7Tn3kvN+kwXpRKyvHQikcRGTLpVVEy/k2mwIVzgNkRXQ5XDOzBSSc+o8\n\tMnNp/AjEPI1NedDTvY7m8764tTdeEvcvUmS4ppkGRVrp0k5FFGnc2Bo+QXUSVr6XDW\n\tzzj+//LyZ3b2EN0cTu+wA9XFdGWG0J8/maMOZXQA=", "From": "Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com>", "To": "libcamera-devel@lists.libcamera.org", "Date": "Wed, 10 Nov 2021 20:58:51 +0100", "Message-Id": "<20211110195901.85597-5-jeanmichel.hautbois@ideasonboard.com>", "X-Mailer": "git-send-email 2.32.0", "In-Reply-To": "<20211110195901.85597-1-jeanmichel.hautbois@ideasonboard.com>", "References": "<20211110195901.85597-1-jeanmichel.hautbois@ideasonboard.com>", "MIME-Version": "1.0", "Content-Transfer-Encoding": "8bit", "Subject": "[libcamera-devel] [PATCH v2 04/14] ipa: ipu3: agc: Limit the number\n\tof saturated cells", "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": "When the histogram is calculated, we check if a cell is saturated or not\nbefore cumulating its green value. This is wrong, and it can lead to an\nempty histogram in case of a fully saturated frame.\n\nUse a constant to limit the amount of pixels within a cell before\nconsidering it saturated. If at the end of the loop we still have an\nempty histogram, then make it a fully saturated one.\n\nBug: https://bugs.libcamera.org/show_bug.cgi?id=84\nSigned-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com>\nReviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>\n---\n src/ipa/ipu3/algorithms/agc.cpp | 16 ++++++++++++++--\n 1 file changed, 14 insertions(+), 2 deletions(-)", "diff": "diff --git a/src/ipa/ipu3/algorithms/agc.cpp b/src/ipa/ipu3/algorithms/agc.cpp\nindex b5d736c1..2bf68e04 100644\n--- a/src/ipa/ipu3/algorithms/agc.cpp\n+++ b/src/ipa/ipu3/algorithms/agc.cpp\n@@ -63,6 +63,12 @@ static constexpr uint32_t knumHistogramBins = 256;\n /* Target value to reach for the top 2% of the histogram */\n static constexpr double kEvGainTarget = 0.5;\n \n+/*\n+ * Maximum ratio of saturated pixels in a cell for the cell to be considered\n+ * non-saturated and counted by the AGC algorithm.\n+ */\n+static constexpr uint32_t kMinCellsPerZoneRatio = 255 * 20 / 100;\n+\n Agc::Agc()\n \t: frameCount_(0), lastFrame_(0), iqMean_(0.0), lineDuration_(0s),\n \t minExposureLines_(0), maxExposureLines_(0), filteredExposure_(0s),\n@@ -124,7 +130,7 @@ void Agc::measureBrightness(const ipu3_uapi_stats_3a *stats,\n \t\t\t\t\t&stats->awb_raw_buffer.meta_data[cellPosition]\n \t\t\t\t);\n \n-\t\t\tif (cell->sat_ratio == 0) {\n+\t\t\tif (cell->sat_ratio <= kMinCellsPerZoneRatio) {\n \t\t\t\tuint8_t gr = cell->Gr_avg;\n \t\t\t\tuint8_t gb = cell->Gb_avg;\n \t\t\t\t/*\n@@ -137,8 +143,14 @@ void Agc::measureBrightness(const ipu3_uapi_stats_3a *stats,\n \t\t}\n \t}\n \n+\tHistogram cumulativeHist = Histogram(Span<uint32_t>(hist));\n \t/* Estimate the quantile mean of the top 2% of the histogram */\n-\tiqMean_ = Histogram(Span<uint32_t>(hist)).interQuantileMean(0.98, 1.0);\n+\tif (cumulativeHist.total() == 0) {\n+\t\t/* Force the value as histogram is empty */\n+\t\tiqMean_ = knumHistogramBins - 0.5;\n+\t} else {\n+\t\tiqMean_ = cumulativeHist.interQuantileMean(0.98, 1.0);\n+\t}\n }\n \n /**\n", "prefixes": [ "libcamera-devel", "v2", "04/14" ] }