From patchwork Fri Sep 20 13:39:22 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Klug X-Patchwork-Id: 21302 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 4E117C3257 for ; Fri, 20 Sep 2024 13:40:14 +0000 (UTC) Received: from lancelot.ideasonboard.com (localhost [IPv6:::1]) by lancelot.ideasonboard.com (Postfix) with ESMTP id EA07E63509; Fri, 20 Sep 2024 15:40:13 +0200 (CEST) Authentication-Results: lancelot.ideasonboard.com; dkim=pass (1024-bit key; unprotected) header.d=ideasonboard.com header.i=@ideasonboard.com header.b="QezgWwBu"; dkim-atps=neutral Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [213.167.242.64]) by lancelot.ideasonboard.com (Postfix) with ESMTPS id 09B1663509 for ; Fri, 20 Sep 2024 15:40:05 +0200 (CEST) Received: from ideasonboard.com (unknown [IPv6:2a00:6020:448c:6c00:8ade:938d:48b1:cede]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 156EF8D4; Fri, 20 Sep 2024 15:38:41 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1726839521; bh=QY84XvVsQpnLAl0zHcYpr4dVqavgW9DRNFbhQ8Dt8+k=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=QezgWwBuJOE15p6TRZmcCvZLcUawXinF9WtvjlCjD1W0pOs8IJJvpicOzHV3F1CFa /eTgxMGZlp+FqdK7MFlF11unKnPfpfcjwEP0szUeVw0iyPusuuwDvGbp+baocGzzgV wnnwsPlICrwWeuLxn/SAj9CfPaY6Jlk0BGOQ2lWo= From: Stefan Klug To: libcamera-devel@lists.libcamera.org Cc: Stefan Klug , Kieran Bingham Subject: [PATCH v3 7/9] ipa: libipa: Add lsc polynomial class Date: Fri, 20 Sep 2024 15:39:22 +0200 Message-ID: <20240920133941.90629-8-stefan.klug@ideasonboard.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240920133941.90629-1-stefan.klug@ideasonboard.com> References: <20240920133941.90629-1-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 a basic class to represent polynomials as specified in the DNG spec for vignetting correction. Signed-off-by: Stefan Klug Reviewed-by: Kieran Bingham --- Changes in v3: - Fixed typos - Fixed unintialized variables - Collected tags --- src/ipa/libipa/lsc_polynomial.cpp | 81 +++++++++++++++++++++++ src/ipa/libipa/lsc_polynomial.h | 105 ++++++++++++++++++++++++++++++ src/ipa/libipa/meson.build | 2 + 3 files changed, 188 insertions(+) create mode 100644 src/ipa/libipa/lsc_polynomial.cpp create mode 100644 src/ipa/libipa/lsc_polynomial.h diff --git a/src/ipa/libipa/lsc_polynomial.cpp b/src/ipa/libipa/lsc_polynomial.cpp new file mode 100644 index 000000000000..f607d86c54c3 --- /dev/null +++ b/src/ipa/libipa/lsc_polynomial.cpp @@ -0,0 +1,81 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ +/* + * Copyright (C) 2024, Ideas On Board + * + * Polynomial class to represent lens shading correction + */ + +#include "lsc_polynomial.h" + +#include + +/** + * \file lsc_polynomial.h + * \brief LscPolynomial class + */ + +namespace libcamera { + +LOG_DEFINE_CATEGORY(LscPolynomial) + +namespace ipa { + +/** + * \class LscPolynomial + * \brief Class for handling even polynomials used in lens shading correction + * + * Shading artifacts of camera lenses can be modeled using even radial + * polynomials. This class implements a polynomial with 5 coefficients which + * follows the definition of the FixVignetteRadial opcode in the Adobe DNG + * specification. + */ + +/** + * \fn LscPolynomial::LscPolynomial(double cx = 0.0, double cy = 0.0, double k0 = 0.0, + double k1 = 0.0, double k2 = 0.0, double k3 = 0.0, + double k4 = 0.0) + * \brief Construct a polynomial using the given coefficients + * \param cx Center-x relative to the image in normalized coordinates (0..1) + * \param cy Center-y relative to the image in normalized coordinates (0..1) + * \param k0 Coefficient of the polynomial + * \param k1 Coefficient of the polynomial + * \param k2 Coefficient of the polynomial + * \param k3 Coefficient of the polynomial + * \param k4 Coefficient of the polynomial + */ + +/** + * \fn LscPolynomial::sampleAtNormalizedPixelPos(double x, double y) + * \brief Sample the polynomial at the given normalized pixel position + * + * This functions samples the polynomial at the given pixel position divided by + * the value returned by getM(). + * + * \param x x position in normalized coordinates + * \param y y position in normalized coordinates + * \return The sampled value + */ + +/** + * \fn LscPolynomial::getM() + * \brief Get the value m as described in the dng specification + * + * Returns m according to dng spec. m represents the Euclidean distance + * (in pixels) from the optical center to the farthest pixel in the + * image. + * + * \return The sampled value + */ + +/** + * \fn LscPolynomial::setReferenceImageSize(const Size &size) + * \brief Set the reference image size + * + * Set the reference image size that is used for subsequent calls to getM() and + * sampleAtNormalizedPixelPos() + * + * \param size The size of the reference image + */ + +} // namespace ipa +} // namespace libcamera diff --git a/src/ipa/libipa/lsc_polynomial.h b/src/ipa/libipa/lsc_polynomial.h new file mode 100644 index 000000000000..c898faeb13db --- /dev/null +++ b/src/ipa/libipa/lsc_polynomial.h @@ -0,0 +1,105 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ +/* + * Copyright (C) 2024, Ideas On Board + * + * Helper for radial polynomial used in lens shading correction. + */ +#pragma once + +#include +#include +#include +#include + +#include +#include + +#include "libcamera/internal/yaml_parser.h" + +namespace libcamera { + +LOG_DECLARE_CATEGORY(LscPolynomial) + +namespace ipa { + +class LscPolynomial +{ +public: + LscPolynomial(double cx = 0.0, double cy = 0.0, double k0 = 0.0, + double k1 = 0.0, double k2 = 0.0, double k3 = 0.0, + double k4 = 0.0) + : cx_(cx), cy_(cy), cnx_(0), cny_(0), + coefficients_({ k0, k1, k2, k3, k4 }) + { + } + + double sampleAtNormalizedPixelPos(double x, double y) const + { + double dx = x - cnx_; + double dy = y - cny_; + double r = sqrt(dx * dx + dy * dy); + double res = 1.0; + for (unsigned int i = 0; i < coefficients_.size(); i++) { + res += coefficients_[i] * std::pow(r, (i + 1) * 2); + } + return res; + } + + double getM() const + { + double cpx = imageSize_.width * cx_; + double cpy = imageSize_.height * cy_; + double mx = std::max(cpx, std::fabs(imageSize_.width - cpx)); + double my = std::max(cpy, std::fabs(imageSize_.height - cpy)); + + return sqrt(mx * mx + my * my); + } + + void setReferenceImageSize(const Size &size) + { + assert(!size.isNull()); + imageSize_ = size; + + /* Calculate normalized centers */ + double m = getM(); + cnx_ = (size.width * cx_) / m; + cny_ = (size.height * cy_) / m; + } + +private: + double cx_; + double cy_; + double cnx_; + double cny_; + std::array coefficients_; + + Size imageSize_; +}; + +} /* namespace ipa */ + +#ifndef __DOXYGEN__ + +template<> +struct YamlObject::Getter { + std::optional get(const YamlObject &obj) const + { + std::optional cx = obj["cx"].get(); + std::optional cy = obj["cy"].get(); + std::optional k0 = obj["k0"].get(); + std::optional k1 = obj["k1"].get(); + std::optional k2 = obj["k2"].get(); + std::optional k3 = obj["k3"].get(); + std::optional k4 = obj["k4"].get(); + + if (!(cx && cy && k0 && k1 && k2 && k3 && k4)) + LOG(LscPolynomial, Error) + << "Polynomial is missing a parameter"; + + return ipa::LscPolynomial(*cx, *cy, *k0, *k1, *k2, *k3, *k4); + } +}; + +#endif + +} /* namespace libcamera */ diff --git a/src/ipa/libipa/meson.build b/src/ipa/libipa/meson.build index 3740178b2909..e78cbcd63633 100644 --- a/src/ipa/libipa/meson.build +++ b/src/ipa/libipa/meson.build @@ -8,6 +8,7 @@ libipa_headers = files([ 'fc_queue.h', 'histogram.h', 'interpolator.h', + 'lsc_polynomial.h', 'matrix.h', 'module.h', 'pwl.h', @@ -22,6 +23,7 @@ libipa_sources = files([ 'fc_queue.cpp', 'histogram.cpp', 'interpolator.cpp', + 'lsc_polynomial.cpp', 'matrix.cpp', 'module.cpp', 'pwl.cpp',