Patch Detail
Show a patch.
GET /api/patches/14456/?format=api
{ "id": 14456, "url": "https://patchwork.libcamera.org/api/patches/14456/?format=api", "web_url": "https://patchwork.libcamera.org/patch/14456/", "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": "<20211104113621.60730-1-jeanmichel.hautbois@ideasonboard.com>", "date": "2021-11-04T11:36:21", "name": "[libcamera-devel,v2] ipa: ipu3: agc: Limit the number of saturated cells", "commit_ref": null, "pull_url": null, "state": "superseded", "archived": false, "hash": "6ea8714a0c33c48552753ac47b93735052f05279", "submitter": { "id": 75, "url":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/14456/mbox/", "series": [ { "id": 2690, "url": "https://patchwork.libcamera.org/api/series/2690/?format=api", "web_url": "https://patchwork.libcamera.org/project/libcamera/list/?series=2690", "date": "2021-11-04T11:36:21", "name": "[libcamera-devel,v2] ipa: ipu3: agc: Limit the number of saturated cells", "version": 2, "mbox": "https://patchwork.libcamera.org/series/2690/mbox/" } ], "comments": "https://patchwork.libcamera.org/api/patches/14456/comments/", "check": "pending", "checks": "https://patchwork.libcamera.org/api/patches/14456/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 1AC1DBF415\n\tfor <parsemail@patchwork.libcamera.org>;\n\tThu, 4 Nov 2021 11:36:27 +0000 (UTC)", "from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id 69E5E6032F;\n\tThu, 4 Nov 2021 12:36:26 +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 362126032C\n\tfor <libcamera-devel@lists.libcamera.org>;\n\tThu, 4 Nov 2021 12:36:25 +0100 (CET)", "from tatooine.ideasonboard.com (unknown\n\t[IPv6:2a01:e0a:169:7140:3875:cc64:ce12:aabc])\n\tby perceval.ideasonboard.com (Postfix) with ESMTPSA id BC4D3E52;\n\tThu, 4 Nov 2021 12:36:24 +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=\"kpk14I+s\"; dkim-atps=neutral", "DKIM-Signature": "v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com;\n\ts=mail; t=1636025784;\n\tbh=hN9HJZvk6P5YS4KN6dKSRegMF8+zEFkQAJWYDuvreGw=;\n\th=From:To:Cc:Subject:Date:From;\n\tb=kpk14I+shW62C+mZ9ZRZsYTlam9bRWjZqZ5wcyw35NtVvMXLzjvtjUWzkMVKgGkCn\n\txyCryZuOAGc7esnX6HLN+yIoUyGNmgJEBWUi+48fFxe+jnDSUZtvTpQzTqawog9V0O\n\tcxWfyCNyse9fkISiS5VK0mZ8FVbBMSc52SsJ6K7c=", "From": "Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com>", "To": "libcamera-devel@lists.libcamera.org", "Date": "Thu, 4 Nov 2021 12:36:21 +0100", "Message-Id": "<20211104113621.60730-1-jeanmichel.hautbois@ideasonboard.com>", "X-Mailer": "git-send-email 2.32.0", "MIME-Version": "1.0", "Content-Transfer-Encoding": "8bit", "Subject": "[libcamera-devel] [PATCH v2] ipa: ipu3: agc: Limit the number of\n\tsaturated 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>\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..dcdfb95c 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 * 50 / 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" ] }