From patchwork Tue Apr 1 12:36:09 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Klug X-Patchwork-Id: 23088 Return-Path: X-Original-To: parsemail@patchwork.libcamera.org Delivered-To: parsemail@patchwork.libcamera.org Received: from lancelot.ideasonboard.com (lancelot.ideasonboard.com [92.243.16.209]) by patchwork.libcamera.org (Postfix) with ESMTPS id 56E3DC3213 for ; Tue, 1 Apr 2025 12:36:43 +0000 (UTC) Received: from lancelot.ideasonboard.com (localhost [IPv6:::1]) by lancelot.ideasonboard.com (Postfix) with ESMTP id 1302F68987; Tue, 1 Apr 2025 14:36:43 +0200 (CEST) Authentication-Results: lancelot.ideasonboard.com; dkim=pass (1024-bit key; unprotected) header.d=ideasonboard.com header.i=@ideasonboard.com header.b="n2smA14J"; dkim-atps=neutral Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [IPv6:2001:4b98:dc2:55:216:3eff:fef7:d647]) by lancelot.ideasonboard.com (Postfix) with ESMTPS id E9E906894F for ; Tue, 1 Apr 2025 14:36:40 +0200 (CEST) Received: from ideasonboard.com (unknown [IPv6:2a00:6020:448c:6c00:14c7:4fcc:495b:719f]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id C97738DB; Tue, 1 Apr 2025 14:34:48 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1743510888; bh=gy7FIKZqYC9JBLNTVCju94reupfL8FANNuHlDHB4j0U=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=n2smA14JlvD5SGhCNNmPeHFsnQQOag+ZuUMtI7xshWUGRpOCL4N68Yb5/c7AFd7XU Z2laO/F/GF70oFnbDTEIzX8Qm7fW6/T7DO9V7De2iGLrnuavtTdi/XovB1Fv6QJWIs AZp9vQTkxsqKmNvXhARqvnoGArRBAIAS2o95mer8= From: Stefan Klug To: libcamera-devel@lists.libcamera.org Cc: Stefan Klug , Kieran Bingham , Laurent Pinchart Subject: [PATCH v2 1/5] test: ipa: libipa: Add histogram tests Date: Tue, 1 Apr 2025 14:36:09 +0200 Message-ID: <20250401123633.58887-2-stefan.klug@ideasonboard.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20250401123633.58887-1-stefan.klug@ideasonboard.com> References: <20250401123633.58887-1-stefan.klug@ideasonboard.com> MIME-Version: 1.0 X-BeenThere: libcamera-devel@lists.libcamera.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: libcamera-devel-bounces@lists.libcamera.org Sender: "libcamera-devel" Add some basic tests for the histogram class. Signed-off-by: Stefan Klug Reviewed-by: Kieran Bingham Reviewed-by: Laurent Pinchart --- Changes in v2: - Replaced printf by std::cout - Collected tags --- test/ipa/libipa/histogram.cpp | 53 +++++++++++++++++++++++++++++++++++ test/ipa/libipa/meson.build | 1 + 2 files changed, 54 insertions(+) create mode 100644 test/ipa/libipa/histogram.cpp diff --git a/test/ipa/libipa/histogram.cpp b/test/ipa/libipa/histogram.cpp new file mode 100644 index 000000000000..312b88b0786b --- /dev/null +++ b/test/ipa/libipa/histogram.cpp @@ -0,0 +1,53 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * Copyright (C) 2024, Ideas on Board Oy + * + * Histogram tests + */ + +#include "../src/ipa/libipa/histogram.h" + +#include +#include +#include +#include + +#include "test.h" + +using namespace std; +using namespace libcamera; +using namespace ipa; + +#define ASSERT_EQ(a, b) \ + if (!((a) == (b))) { \ + std::cout << #a " != " #b << std::endl; \ + return TestFail; \ + } + +class HistogramTest : public Test +{ +protected: + int run() + { + auto hist = Histogram({ { 50, 50 } }); + + ASSERT_EQ(hist.bins(), 2); + ASSERT_EQ(hist.total(), 100); + + ASSERT_EQ(hist.cumulativeFrequency(1.0), 50); + ASSERT_EQ(hist.cumulativeFrequency(1.5), 75); + ASSERT_EQ(hist.cumulativeFrequency(2.0), 100); + + ASSERT_EQ(hist.quantile(0.0), 0.0); + ASSERT_EQ(hist.quantile(1.0), 2.0); + ASSERT_EQ(hist.quantile(0.5), 1.0); + + ASSERT_EQ(hist.interQuantileMean(0.0, 1.0), 1.0); + ASSERT_EQ(hist.interQuantileMean(0.0, 0.5), 0.5); + ASSERT_EQ(hist.interQuantileMean(0.5, 1.0), 1.5); + + return TestPass; + } +}; + +TEST_REGISTER(HistogramTest) diff --git a/test/ipa/libipa/meson.build b/test/ipa/libipa/meson.build index eaf4b49a187c..f094c1593f1b 100644 --- a/test/ipa/libipa/meson.build +++ b/test/ipa/libipa/meson.build @@ -2,6 +2,7 @@ libipa_test = [ {'name': 'fixedpoint', 'sources': ['fixedpoint.cpp']}, + {'name': 'histogram', 'sources': ['histogram.cpp']}, {'name': 'interpolator', 'sources': ['interpolator.cpp']}, ] From patchwork Tue Apr 1 12:36:10 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Klug X-Patchwork-Id: 23089 Return-Path: X-Original-To: parsemail@patchwork.libcamera.org Delivered-To: parsemail@patchwork.libcamera.org Received: from lancelot.ideasonboard.com (lancelot.ideasonboard.com [92.243.16.209]) by patchwork.libcamera.org (Postfix) with ESMTPS id BEFC4C3213 for ; Tue, 1 Apr 2025 12:36:45 +0000 (UTC) Received: from lancelot.ideasonboard.com (localhost [IPv6:::1]) by lancelot.ideasonboard.com (Postfix) with ESMTP id 81E246898A; Tue, 1 Apr 2025 14:36:45 +0200 (CEST) Authentication-Results: lancelot.ideasonboard.com; dkim=pass (1024-bit key; unprotected) header.d=ideasonboard.com header.i=@ideasonboard.com header.b="U18J/qYK"; dkim-atps=neutral Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [213.167.242.64]) by lancelot.ideasonboard.com (Postfix) with ESMTPS id F264D68986 for ; Tue, 1 Apr 2025 14:36:43 +0200 (CEST) Received: from ideasonboard.com (unknown [IPv6:2a00:6020:448c:6c00:14c7:4fcc:495b:719f]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id D5B668DB; Tue, 1 Apr 2025 14:34:51 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1743510891; bh=GZmB11y+IhtBtTi7bnLPo96lf/dc+fT1pp9i/K/fHhY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=U18J/qYKdKeUiRPwv5lIaUFKsxXpmpLvbYNyAqcWrIjtRtNu0p4q0AVpTSgcY0myL RNEufyMcQUKKmhO4E/7XoB/GJ/bZIn8XOqE+8mm6YzWNnejdJ1JybvW9sK5CwfvKQj s+hvMBx8taYwua4+W/oPt0UHfAtvdnq8cuAWxlb4= From: Stefan Klug To: libcamera-devel@lists.libcamera.org Cc: Stefan Klug , Kieran Bingham , Laurent Pinchart Subject: [PATCH v2 2/5] test: ipa: libipa: histogram: Add tests for quantile() returning a fraction Date: Tue, 1 Apr 2025 14:36:10 +0200 Message-ID: <20250401123633.58887-3-stefan.klug@ideasonboard.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20250401123633.58887-1-stefan.klug@ideasonboard.com> References: <20250401123633.58887-1-stefan.klug@ideasonboard.com> MIME-Version: 1.0 X-BeenThere: libcamera-devel@lists.libcamera.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: libcamera-devel-bounces@lists.libcamera.org Sender: "libcamera-devel" Add tests for quantile() returning a fractional value. These cases will get fixed in the next commit. Therefore mark the test as should_fail. Signed-off-by: Stefan Klug Reviewed-by: Kieran Bingham Reviewed-by: Laurent Pinchart --- Changes in v2: - Move test patch before fix and add should_fail. - Fixed comment - Collected tags --- test/ipa/libipa/histogram.cpp | 9 +++++++++ test/ipa/libipa/meson.build | 5 +++-- 2 files changed, 12 insertions(+), 2 deletions(-) diff --git a/test/ipa/libipa/histogram.cpp b/test/ipa/libipa/histogram.cpp index 312b88b0786b..5ce84a61b7da 100644 --- a/test/ipa/libipa/histogram.cpp +++ b/test/ipa/libipa/histogram.cpp @@ -42,10 +42,19 @@ protected: ASSERT_EQ(hist.quantile(1.0), 2.0); ASSERT_EQ(hist.quantile(0.5), 1.0); + /* Test quantile in the middle of a bin. */ + ASSERT_EQ(hist.quantile(0.75), 1.5); + + /* Test quantile smaller than the smallest histogram step. */ + ASSERT_EQ(hist.quantile(0.001), 0.002); + ASSERT_EQ(hist.interQuantileMean(0.0, 1.0), 1.0); ASSERT_EQ(hist.interQuantileMean(0.0, 0.5), 0.5); ASSERT_EQ(hist.interQuantileMean(0.5, 1.0), 1.5); + /* Test interquantile mean that starts and ends in the middle of a bin. */ + ASSERT_EQ(hist.interQuantileMean(0.25, 0.75), 1.0); + return TestPass; } }; diff --git a/test/ipa/libipa/meson.build b/test/ipa/libipa/meson.build index f094c1593f1b..83c84bd8c227 100644 --- a/test/ipa/libipa/meson.build +++ b/test/ipa/libipa/meson.build @@ -2,7 +2,7 @@ libipa_test = [ {'name': 'fixedpoint', 'sources': ['fixedpoint.cpp']}, - {'name': 'histogram', 'sources': ['histogram.cpp']}, + {'name': 'histogram', 'sources': ['histogram.cpp'], 'should_fail': true}, {'name': 'interpolator', 'sources': ['interpolator.cpp']}, ] @@ -14,5 +14,6 @@ foreach test : libipa_test include_directories : [test_includes_internal, '../../../src/ipa/libipa/']) - test(test['name'], exe, suite : 'ipa') + test(test['name'], exe, suite : 'ipa', + should_fail : test.get('should_fail', false)) endforeach From patchwork Tue Apr 1 12:36:11 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Klug X-Patchwork-Id: 23090 Return-Path: X-Original-To: parsemail@patchwork.libcamera.org Delivered-To: parsemail@patchwork.libcamera.org Received: from lancelot.ideasonboard.com (lancelot.ideasonboard.com [92.243.16.209]) by patchwork.libcamera.org (Postfix) with ESMTPS id 846DCC3213 for ; Tue, 1 Apr 2025 12:36:49 +0000 (UTC) Received: from lancelot.ideasonboard.com (localhost [IPv6:::1]) by lancelot.ideasonboard.com (Postfix) with ESMTP id 456686898A; Tue, 1 Apr 2025 14:36:49 +0200 (CEST) Authentication-Results: lancelot.ideasonboard.com; dkim=pass (1024-bit key; unprotected) header.d=ideasonboard.com header.i=@ideasonboard.com header.b="ApnMNn2I"; dkim-atps=neutral Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [IPv6:2001:4b98:dc2:55:216:3eff:fef7:d647]) by lancelot.ideasonboard.com (Postfix) with ESMTPS id 81CE568987 for ; Tue, 1 Apr 2025 14:36:47 +0200 (CEST) Received: from ideasonboard.com (unknown [IPv6:2a00:6020:448c:6c00:14c7:4fcc:495b:719f]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 57E128DB; Tue, 1 Apr 2025 14:34:55 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1743510895; bh=l3JdK+kvaObWpCAA5lqKijrnmQNvjPFPucRyBvKUfMI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ApnMNn2IabMUGMW2FhdyR56T9SG+GgjsmcIqMszJ527Y+5YZlyB5Bz/W8lal+zrwn 5JcpdLpp8kpn3fuUYCOUleJcQXlmGAKCtgvlSj/fr6OQ9jqNqjXRbKPsN9au6Jqe6i UXeSnzk2S1wScCKuZuQhOYoSRIp0Z8doS+GPFqSk= From: Stefan Klug To: libcamera-devel@lists.libcamera.org Cc: Stefan Klug , Kieran Bingham , Laurent Pinchart Subject: [PATCH v2 3/5] libipa: histogram: Fix quantile() calculation for fractional results Date: Tue, 1 Apr 2025 14:36:11 +0200 Message-ID: <20250401123633.58887-4-stefan.klug@ideasonboard.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20250401123633.58887-1-stefan.klug@ideasonboard.com> References: <20250401123633.58887-1-stefan.klug@ideasonboard.com> MIME-Version: 1.0 X-BeenThere: libcamera-devel@lists.libcamera.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: libcamera-devel-bounces@lists.libcamera.org Sender: "libcamera-devel" The calculation of the frac variable is based solely on integers and therefore results in the fractional part being either 0 or 1. In the original code from RaspberryPi this is mitigated by casting the nominator to a double. This works for most cases, but fails when q is very small because of the quantization introduced by item being an integer. Fix both issues by doing the full calculation in double and remove the should_fail tag. Signed-off-by: Stefan Klug Reviewed-by: Kieran Bingham Reviewed-by: Laurent Pinchart --- Changes in v2: - Order fix patch after test - Remove should_fail tag - Break line before operator instead of after --- src/ipa/libipa/histogram.cpp | 3 ++- test/ipa/libipa/meson.build | 2 +- 2 files changed, 3 insertions(+), 2 deletions(-) diff --git a/src/ipa/libipa/histogram.cpp b/src/ipa/libipa/histogram.cpp index 10e44b54a0cf..ea042f0a17b9 100644 --- a/src/ipa/libipa/histogram.cpp +++ b/src/ipa/libipa/histogram.cpp @@ -130,7 +130,8 @@ double Histogram::quantile(double q, uint32_t first, uint32_t last) const if (cumulative_[first + 1] == cumulative_[first]) frac = 0; else - frac = (item - cumulative_[first]) / (cumulative_[first + 1] - cumulative_[first]); + frac = (q * total() - cumulative_[first]) + / (cumulative_[first + 1] - cumulative_[first]); return first + frac; } diff --git a/test/ipa/libipa/meson.build b/test/ipa/libipa/meson.build index 83c84bd8c227..8c63ebd8e2f7 100644 --- a/test/ipa/libipa/meson.build +++ b/test/ipa/libipa/meson.build @@ -2,7 +2,7 @@ libipa_test = [ {'name': 'fixedpoint', 'sources': ['fixedpoint.cpp']}, - {'name': 'histogram', 'sources': ['histogram.cpp'], 'should_fail': true}, + {'name': 'histogram', 'sources': ['histogram.cpp']}, {'name': 'interpolator', 'sources': ['interpolator.cpp']}, ] From patchwork Tue Apr 1 12:36:12 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Klug X-Patchwork-Id: 23091 Return-Path: X-Original-To: parsemail@patchwork.libcamera.org Delivered-To: parsemail@patchwork.libcamera.org Received: from lancelot.ideasonboard.com (lancelot.ideasonboard.com [92.243.16.209]) by patchwork.libcamera.org (Postfix) with ESMTPS id ED12EC3213 for ; Tue, 1 Apr 2025 12:36:51 +0000 (UTC) Received: from lancelot.ideasonboard.com (localhost [IPv6:::1]) by lancelot.ideasonboard.com (Postfix) with ESMTP id B1A3868992; Tue, 1 Apr 2025 14:36:51 +0200 (CEST) Authentication-Results: lancelot.ideasonboard.com; dkim=pass (1024-bit key; unprotected) header.d=ideasonboard.com header.i=@ideasonboard.com header.b="NVtYhmM6"; dkim-atps=neutral Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [IPv6:2001:4b98:dc2:55:216:3eff:fef7:d647]) by lancelot.ideasonboard.com (Postfix) with ESMTPS id E00526898F for ; Tue, 1 Apr 2025 14:36:50 +0200 (CEST) Received: from ideasonboard.com (unknown [IPv6:2a00:6020:448c:6c00:14c7:4fcc:495b:719f]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id AF87D8DB; Tue, 1 Apr 2025 14:34:58 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1743510898; bh=ox6fwJY1Ya93M7EtZYsXdTbgTfh/Y5fhG4FI2/TW//E=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=NVtYhmM6f0l6CT1b/QQjglpZ11wNbnF+VPkU+udRfwhybL2P9coQEJ0B/1zoDS07k UtPxWJlo+RVzI0t/1SDGKFgRiG03wkq5wIcvEZSEnjo13ioNQ7CymD9UQurr4DblSD w6mQQue+OqGqhyzMR9q+FQtKT5T+0G+gjHrCLtug= From: Stefan Klug To: libcamera-devel@lists.libcamera.org Cc: Stefan Klug , Kieran Bingham , Laurent Pinchart Subject: [PATCH v2 4/5] test: ipa: libipa: histogram: Add tests for small inter quantile mean ranges Date: Tue, 1 Apr 2025 14:36:12 +0200 Message-ID: <20250401123633.58887-5-stefan.klug@ideasonboard.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20250401123633.58887-1-stefan.klug@ideasonboard.com> References: <20250401123633.58887-1-stefan.klug@ideasonboard.com> MIME-Version: 1.0 X-BeenThere: libcamera-devel@lists.libcamera.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: libcamera-devel-bounces@lists.libcamera.org Sender: "libcamera-devel" Add tests for small inter quantile mean ranges. As these cases fail at the moment, mark the test as should_fail. Signed-off-by: Stefan Klug Reviewed-by: Kieran Bingham Reviewed-by: Laurent Pinchart --- Changes in v2: - Move test patch before fix - Add should_fail - Fix typo in comment --- test/ipa/libipa/histogram.cpp | 4 ++++ test/ipa/libipa/meson.build | 2 +- 2 files changed, 5 insertions(+), 1 deletion(-) diff --git a/test/ipa/libipa/histogram.cpp b/test/ipa/libipa/histogram.cpp index 5ce84a61b7da..77ff31a6db0e 100644 --- a/test/ipa/libipa/histogram.cpp +++ b/test/ipa/libipa/histogram.cpp @@ -55,6 +55,10 @@ protected: /* Test interquantile mean that starts and ends in the middle of a bin. */ ASSERT_EQ(hist.interQuantileMean(0.25, 0.75), 1.0); + /* Test small ranges at the borders of the histogram. */ + ASSERT_EQ(hist.interQuantileMean(0.0, 0.1), 0.1); + ASSERT_EQ(hist.interQuantileMean(0.9, 1.0), 1.9); + return TestPass; } }; diff --git a/test/ipa/libipa/meson.build b/test/ipa/libipa/meson.build index 8c63ebd8e2f7..83c84bd8c227 100644 --- a/test/ipa/libipa/meson.build +++ b/test/ipa/libipa/meson.build @@ -2,7 +2,7 @@ libipa_test = [ {'name': 'fixedpoint', 'sources': ['fixedpoint.cpp']}, - {'name': 'histogram', 'sources': ['histogram.cpp']}, + {'name': 'histogram', 'sources': ['histogram.cpp'], 'should_fail': true}, {'name': 'interpolator', 'sources': ['interpolator.cpp']}, ] From patchwork Tue Apr 1 12:36:13 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Klug X-Patchwork-Id: 23092 Return-Path: X-Original-To: parsemail@patchwork.libcamera.org Delivered-To: parsemail@patchwork.libcamera.org Received: from lancelot.ideasonboard.com (lancelot.ideasonboard.com [92.243.16.209]) by patchwork.libcamera.org (Postfix) with ESMTPS id 9A312C3213 for ; Tue, 1 Apr 2025 12:36:56 +0000 (UTC) Received: from lancelot.ideasonboard.com (localhost [IPv6:::1]) by lancelot.ideasonboard.com (Postfix) with ESMTP id 53C9768991; Tue, 1 Apr 2025 14:36:56 +0200 (CEST) Authentication-Results: lancelot.ideasonboard.com; dkim=pass (1024-bit key; unprotected) header.d=ideasonboard.com header.i=@ideasonboard.com header.b="AyH8eUBd"; dkim-atps=neutral Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [IPv6:2001:4b98:dc2:55:216:3eff:fef7:d647]) by lancelot.ideasonboard.com (Postfix) with ESMTPS id E73F66898A for ; Tue, 1 Apr 2025 14:36:53 +0200 (CEST) Received: from ideasonboard.com (unknown [IPv6:2a00:6020:448c:6c00:14c7:4fcc:495b:719f]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id CA2968DB; Tue, 1 Apr 2025 14:35:01 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1743510901; bh=bUNDK7vLq1vWyOMPzMZ+ZDpn7eKJqeahqSjxAG4P9vE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=AyH8eUBdAqscnPyY8wzlkNDpxBLvUDycIIwG7hpqSusEAKoI0diQAO9jkFlOyv02z z7g3Z9UkJ3KrOe9PnUT0u+FSl57Op/eXFQgUhi5aePRuXNm4eZ2R7Yli5By1GWdus0 mFf3Gv3utMV0Ew2N4q6lFuymSIts8PpyCIkGXV3g= From: Stefan Klug To: libcamera-devel@lists.libcamera.org Cc: Stefan Klug , Kieran Bingham , Laurent Pinchart Subject: [PATCH v2 5/5] libipa: histogram: Fix interQuantileMean() for small ranges Date: Tue, 1 Apr 2025 14:36:13 +0200 Message-ID: <20250401123633.58887-6-stefan.klug@ideasonboard.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20250401123633.58887-1-stefan.klug@ideasonboard.com> References: <20250401123633.58887-1-stefan.klug@ideasonboard.com> MIME-Version: 1.0 X-BeenThere: libcamera-devel@lists.libcamera.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: libcamera-devel-bounces@lists.libcamera.org Sender: "libcamera-devel" The interQuantileMean() is supposed to return a weighted mean value between two quantiles. This works for fine histograms, but fails for coarse histograms and small quantile ranges because the weight is always taken from the lower border of the bin. Fix that by rewriting the algorithm to calculate a lower and upper bound for every (partial) bin that goes into the mean calculation and weight the bins by the middle of these bounds. Signed-off-by: Stefan Klug Acked-by: Kieran Bingham Reviewed-by: Laurent Pinchart --- Changes in v2: - Order fix patch after test patch - Remove should_fail - Added documentation based on review - Improved code style based on review --- src/ipa/libipa/histogram.cpp | 39 +++++++++++++++++++++++------------- test/ipa/libipa/meson.build | 2 +- 2 files changed, 26 insertions(+), 15 deletions(-) diff --git a/src/ipa/libipa/histogram.cpp b/src/ipa/libipa/histogram.cpp index ea042f0a17b9..bcf263908236 100644 --- a/src/ipa/libipa/histogram.cpp +++ b/src/ipa/libipa/histogram.cpp @@ -149,26 +149,37 @@ double Histogram::quantile(double q, uint32_t first, uint32_t last) const double Histogram::interQuantileMean(double lowQuantile, double highQuantile) const { ASSERT(highQuantile > lowQuantile); - /* Proportion of pixels which lies below lowQuantile */ - double lowPoint = quantile(lowQuantile); - /* Proportion of pixels which lies below highQuantile */ - double highPoint = quantile(highQuantile, static_cast(lowPoint)); - double sumBinFreq = 0, cumulFreq = 0; - - for (double p_next = floor(lowPoint) + 1.0; - p_next <= ceil(highPoint); - lowPoint = p_next, p_next += 1.0) { - int bin = floor(lowPoint); + + /* Proportion of pixels which lies below lowQuantile and highQuantile. */ + const double lowPoint = quantile(lowQuantile); + const double highPoint = quantile(highQuantile, static_cast(lowPoint)); + + double sumBinFreq = 0; + double cumulFreq = 0; + + /* + * Calculate the mean pixel value between the low and high points by + * summing all the pixels between the two points, and dividing the sum + * by the number of pixels. Given the discrete nature of the histogram + * data, the sum of the pixels is approximated by accumulating the + * product of the bin values (calculated as the mid point of the bin) by + * the number of pixels they contain, for each bin in the internal. + */ + for (unsigned bin = std::floor(lowPoint); bin < std::ceil(highPoint); bin++) { + const double lowBound = std::max(bin, lowPoint); + const double highBound = std::min(bin + 1, highPoint); + double freq = (cumulative_[bin + 1] - cumulative_[bin]) - * (std::min(p_next, highPoint) - lowPoint); + * (highBound - lowBound); /* Accumulate weighted bin */ - sumBinFreq += bin * freq; + sumBinFreq += (highBound + lowBound) / 2 * freq; + /* Accumulate weights */ cumulFreq += freq; } - /* add 0.5 to give an average for bin mid-points */ - return sumBinFreq / cumulFreq + 0.5; + + return sumBinFreq / cumulFreq; } } /* namespace ipa */ diff --git a/test/ipa/libipa/meson.build b/test/ipa/libipa/meson.build index 83c84bd8c227..8c63ebd8e2f7 100644 --- a/test/ipa/libipa/meson.build +++ b/test/ipa/libipa/meson.build @@ -2,7 +2,7 @@ libipa_test = [ {'name': 'fixedpoint', 'sources': ['fixedpoint.cpp']}, - {'name': 'histogram', 'sources': ['histogram.cpp'], 'should_fail': true}, + {'name': 'histogram', 'sources': ['histogram.cpp']}, {'name': 'interpolator', 'sources': ['interpolator.cpp']}, ]