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']}, ]