[{"id":29193,"web_url":"https://patchwork.libcamera.org/comment/29193/","msgid":"<20240410215249.e3u2lqw5ptgkxdb5@macbook-air>","date":"2024-04-10T21:52:49","subject":"Re: [PATCH 2/3] ipa: libipa: Add MatrixInterpolator class","submitter":{"id":184,"url":"https://patchwork.libcamera.org/api/people/184/","name":"Stefan Klug","email":"stefan.klug@ideasonboard.com"},"content":"Hi Paul,\n\nthank you for the patch. \n\nOn Fri, Apr 05, 2024 at 05:40:49PM +0900, Paul Elder wrote:\n> Add a class to encapsulate the functionality of fetching a matrix based\n> on an integer key, and interpolating if there is no exact match. This is\n> expected to be used by both color correction matrices / crosstalk\n> correction as well as lens shading correction.\n> \n> Signed-off-by: Paul Elder \n> ---\n> src/ipa/libipa/matrix_interpolator.cpp | 54 +++++++++++++++\n> src/ipa/libipa/matrix_interpolator.h | 94 ++++++++++++++++++++++++++\n> src/ipa/libipa/meson.build | 2 +\n> 3 files changed, 150 insertions(+)\n> create mode 100644 src/ipa/libipa/matrix_interpolator.cpp\n> create mode 100644 src/ipa/libipa/matrix_interpolator.h\n> \n> diff --git a/src/ipa/libipa/matrix_interpolator.cpp b/src/ipa/libipa/matrix_interpolator.cpp\n> new file mode 100644\n> index 00000000..394633b5\n> --- /dev/null\n> +++ b/src/ipa/libipa/matrix_interpolator.cpp\n> @@ -0,0 +1,54 @@\n> +/* SPDX-License-Identifier: BSD-2-Clause */\n> +/*\n> + * Copyright (C) 2019, Raspberry Pi Ltd\n> + * Copyright (C) 2024, Paul Elder \n> + *\n> + * matrix_interpolator.cpp - Helper class for interpolating maps of matrices\n> + */\n> +#include \"matrix_interpolator.h\"\n> +\n> +#include \n> +#include \n> +\n> +#include \n> +\n> +#include \"libcamera/internal/yaml_parser.h\"\n> +\n> +#include \"matrix.h\"\n> +\n> +/**\n> + * \\file ccm.h\n> + * \\brief Helper class for interpolating maps of matrices\n> + */\n> +\n> +namespace libcamera {\n> +\n> +LOG_DEFINE_CATEGORY(MatrixInterpolator)\n> +\n> +namespace ipa {\n> +\n> +/**\n> + * \\class MatrixInterpolator\n> + * \\brief Class for storing, retrieving, and interpolating matrices\n> + */\n> +\n> +/**\n> + * \\fn int MatrixInterpolator::readYaml(const libcamera::YamlObject &yaml)\n> + * \\brief Initialize an MatrixInterpolator instance from yaml\n> + * \\tparam T Type of data stored in the matrices\n> + * \\tparam R Number of rows of the matrices\n> + * \\tparam C Number of columns of the matrices\n> + * \\param[in] yaml The yaml object that contains the map of unsigned integers to matrices\n> + * \\return Zero on success, negative error code otherwise\n> + */\n> +\n> +/**\n> + * \\fn Matrix MatrixInterpolator::get(unsigned int key)\n> + * \\brief Retrieve a matrix from the list of matrices, interpolating if necessary\n> + * \\param[in] key The unsigned integer key of the matrix to retrieve\n> + * \\return The matrix corresponding to the color temperature\n> + */\n> +\n> +} /* namespace ipa */\n> +\n> +} /* namespace libcamera */\n> diff --git a/src/ipa/libipa/matrix_interpolator.h b/src/ipa/libipa/matrix_interpolator.h\n> new file mode 100644\n> index 00000000..2cd4ff75\n> --- /dev/null\n> +++ b/src/ipa/libipa/matrix_interpolator.h\n> @@ -0,0 +1,94 @@\n> +/* SPDX-License-Identifier: BSD-2-Clause */\n> +/*\n> + * Copyright (C) 2019, Raspberry Pi Ltd\n> + * Copyright (C) 2024, Paul Elder \n> + *\n> + * matrix_interpolator.h - Helper class for interpolating maps of matrices\n> + */\n> +\n> +#pragma once\n> +\n> +#include \n> +#include \n> +#include \n> +#include \n> +\n> +#include \n> +\n> +#include \"libcamera/internal/yaml_parser.h\"\n> +\n> +#include \"matrix.h\"\n> +\n> +namespace libcamera {\n> +\n> +LOG_DECLARE_CATEGORY(MatrixInterpolator)\n> +\n> +namespace ipa {\n> +\n> +template\n\nWhy does this class use template paramters for rows and cols and the\nmatrix class does not? I thought about suggesting these tempate params\non the matrix class, but did not due to simplicity reasons. I believe\nthese should be symetrical. So R and C should also be members here.\n\n> +class MatrixInterpolator\n> +{\n> +public:\n> +\tMatrixInterpolator(){};\n> +\t~MatrixInterpolator(){};\n> +\n> +\tint readYaml(const libcamera::YamlObject &yaml)\n> +\t{\n> +\t\tint ret;\n> +\n> +\t\tif (!yaml.isDictionary()) {\n> +\t\t\tLOG(MatrixInterpolator, Error) << \"yaml object must be a dictionary\";\n> +\t\t\treturn -EINVAL;\n> +\t\t}\n> +\n> +\t\tfor (const auto &[ctStr, value] : yaml.asDict()) {\n> +\t\t\tunsigned int ct = std::stoul(ctStr);\n> +\t\t\tMatrix matrix;\n> +\t\t\tif ((ret = matrix.readYaml(R, C, value)) < 0) {\n> +\t\t\t\tLOG(MatrixInterpolator, Error) << \"Failed to read matrix\";\n> +\t\t\t\treturn ret;\n> +\t\t\t}\n> +\n> +\t\t\tmatrices_[ct] = matrix;\n> +\n> +\t\t\tLOG(MatrixInterpolator, Debug)\n> +\t\t\t\t<< \"Read matrix for key \" << ct << \": \"\n> +\t\t\t\t<< matrices_[ct].toString();\n> +\t\t}\n> +\n> +\t\tif (matrices_.size() < 1) {\n> +\t\t\tLOG(MatrixInterpolator, Error) << \"Need at least one matrix\";\n> +\t\t\treturn -EINVAL;\n> +\t\t}\n> +\n> +\t\treturn 0;\n> +\t}\n> +\n> +\tMatrix get(unsigned int ct)\n> +\t{\n> +\t\tif (matrices_.size() == 1 ||\n> +\t\t ct <= matrices_.begin()->first)\n> +\t\t\treturn matrices_.begin()->second;\n> +\n> +\t\tif (ct >= matrices_.rbegin()->first)\n> +\t\t\treturn matrices_.rbegin()->second;\n> +\n> +\t\tif (matrices_.count(ct))\n> +\t\t\treturn matrices_[ct];\n> +\n> +\t\t/* The above four guarantee that this will succeed */\n> +\t\tauto iter = matrices_.upper_bound(ct);\n> +\t\tunsigned int ctUpper = iter->first;\n> +\t\tunsigned int ctLower = (--iter)->first;\n> +\n> +\t\tdouble lambda = (ct - ctLower) / (ctUpper - ctLower);\n\nBoth sides of the division are integers, so the division will result in\nan integer. I think the denominator must be cast to double or am I\nmissing something here?\n\nThat would be a good case for a small unit test. Simple to write but\nsaves hours of debugging later.\n\n> +\t\treturn lambda * matrices_[ctUpper] + (1.0 - lambda) * matrices_[ctLower];\n> +\t}\n> +\n> +private:\n> +\tstd::map> matrices_;\n> +};\n> +\n> +} /* namespace ipa */\n> +\n> +} /* namespace libcamera */\n> diff --git a/src/ipa/libipa/meson.build b/src/ipa/libipa/meson.build\n> index 5d5ba5e5..128de712 100644\n> --- a/src/ipa/libipa/meson.build\n> +++ b/src/ipa/libipa/meson.build\n> @@ -3,6 +3,7 @@\n> libipa_headers = files([\n> 'algorithm.h',\n> 'camera_sensor_helper.h',\n> + 'matrix_interpolator.h',\n\nThese should be sorted alphabetically.\n\n> 'exposure_mode_helper.h',\n> 'fc_queue.h',\n> 'histogram.h',\n> @@ -14,6 +15,7 @@ libipa_headers = files([\n> libipa_sources = files([\n> 'algorithm.cpp',\n> 'camera_sensor_helper.cpp',\n> + 'matrix_interpolator.cpp',\n\nlikewise\n\n> 'exposure_mode_helper.cpp',\n> 'fc_queue.cpp',\n> 'histogram.cpp',\n> -- \n> 2.39.2\n> \n\nBest regards,\nStefan","headers":{"Return-Path":"","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 34E41BE08B\n\tfor ;\n\tWed, 10 Apr 2024 21:52:56 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id 0D72163339;\n\tWed, 10 Apr 2024 23:52:55 +0200 (CEST)","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 AD32761B8D\n\tfor ;\n\tWed, 10 Apr 2024 23:52:52 +0200 (CEST)","from ideasonboard.com\n\t(p200300cd3f2c2e00d7b53aefac1fc2ef.dip0.t-ipconnect.de\n\t[IPv6:2003:cd:3f2c:2e00:d7b5:3aef:ac1f:c2ef])\n\tby perceval.ideasonboard.com (Postfix) with ESMTPSA id 255F63A4;\n\tWed, 10 Apr 2024 23:52:10 +0200 (CEST)"],"Authentication-Results":"lancelot.ideasonboard.com; dkim=pass (1024-bit key;\n\tunprotected) header.d=ideasonboard.com header.i=@ideasonboard.com\n\theader.b=\"GIwcPsL1\"; dkim-atps=neutral","DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com;\n\ts=mail; t=1712785930;\n\tbh=McugL9TrmGoVR95vC1gfbW3yE/CckB78XcvUltQRd1M=;\n\th=Date:From:To:Cc:Subject:References:In-Reply-To:From;\n\tb=GIwcPsL1cegqe/Og9+PX29Mf8iRoY8jLTrvccau+jLvic2kc79YVF8guofdnRqAHX\n\ts9S+VDVBhHhj3bHIhgJ+I3DOcPFJuMjW+rh7fQMmeHnHpCaP9mIj+n5pmbyebRdWxC\n\tHXBaZPxNU2SNe/tkTpqH5uELxhKslOETrd+8/4dE=","Date":"Wed, 10 Apr 2024 23:52:49 +0200","From":"Stefan Klug ","To":"Paul Elder ","Cc":"libcamera-devel@lists.libcamera.org","Subject":"Re: [PATCH 2/3] ipa: libipa: Add MatrixInterpolator class","Message-ID":"<20240410215249.e3u2lqw5ptgkxdb5@macbook-air>","References":"<20240405084050.1919105-1-paul.elder@ideasonboard.com>\n\t<20240405084050.1919105-3-paul.elder@ideasonboard.com>","MIME-Version":"1.0","Content-Type":"text/plain; charset=utf-8","Content-Disposition":"inline","In-Reply-To":"<20240405084050.1919105-3-paul.elder@ideasonboard.com>","X-BeenThere":"libcamera-devel@lists.libcamera.org","X-Mailman-Version":"2.1.29","Precedence":"list","List-Id":"","List-Unsubscribe":",\n\t","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n\t","Errors-To":"libcamera-devel-bounces@lists.libcamera.org","Sender":"\"libcamera-devel\" "}}]