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sungloksunglok
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Add line fitting with RANSAC
1 parent 9df5d66 commit c5adbc4

4 files changed

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‎msvs/3dv_tutorial.sln‎

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@@ -23,6 +23,8 @@ Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "triangulation", "triangulat
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EndProject
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Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "bundle_adjustment", "bundle_adjustment\bundle_adjustment.vcxproj", "{968A197A-66E1-499E-B3DE-E7760D74081B}"
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EndProject
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Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "ransac_line", "ransac_line\ransac_line.vcxproj", "{53D993B4-1B33-4C18-B279-B77B17517278}"
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EndProject
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Global
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GlobalSection(SolutionConfigurationPlatforms) = preSolution
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Debug|Win32 = Debug|Win32
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{968A197A-66E1-499E-B3DE-E7760D74081B}.Debug|Win32.Build.0 = Debug|Win32
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{968A197A-66E1-499E-B3DE-E7760D74081B}.Release|Win32.ActiveCfg = Release|Win32
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{968A197A-66E1-499E-B3DE-E7760D74081B}.Release|Win32.Build.0 = Release|Win32
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{53D993B4-1B33-4C18-B279-B77B17517278}.Debug|Win32.ActiveCfg = Debug|Win32
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{53D993B4-1B33-4C18-B279-B77B17517278}.Debug|Win32.Build.0 = Debug|Win32
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{53D993B4-1B33-4C18-B279-B77B17517278}.Release|Win32.ActiveCfg = Release|Win32
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{53D993B4-1B33-4C18-B279-B77B17517278}.Release|Win32.Build.0 = Release|Win32
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EndGlobalSection
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GlobalSection(SolutionProperties) = preSolution
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HideSolutionNode = FALSE

‎msvs/ransac_line/ransac_line.vcxproj‎

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<?xml version="1.0" encoding="utf-8"?>
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<Project DefaultTargets="Build" ToolsVersion="12.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
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<ItemGroup Label="ProjectConfigurations">
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<ProjectConfiguration Include="Debug|Win32">
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<Configuration>Debug</Configuration>
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<Platform>Win32</Platform>
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</ProjectConfiguration>
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<ProjectConfiguration Include="Release|Win32">
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<Configuration>Release</Configuration>
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<Platform>Win32</Platform>
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</ProjectConfiguration>
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</ItemGroup>
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<PropertyGroup Label="Globals">
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<ProjectGuid>{53D993B4-1B33-4C18-B279-B77B17517278}</ProjectGuid>
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<Keyword>Win32Proj</Keyword>
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<RootNamespace>3dv_tutorial</RootNamespace>
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</PropertyGroup>
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<Import Project="$(VCTargetsPath)\Microsoft.Cpp.Default.props" />
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<PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'" Label="Configuration">
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<ConfigurationType>Application</ConfigurationType>
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<UseDebugLibraries>true</UseDebugLibraries>
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<PlatformToolset>v120</PlatformToolset>
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<CharacterSet>Unicode</CharacterSet>
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</PropertyGroup>
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<PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'" Label="Configuration">
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<ConfigurationType>Application</ConfigurationType>
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<UseDebugLibraries>false</UseDebugLibraries>
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<PlatformToolset>v120</PlatformToolset>
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<WholeProgramOptimization>true</WholeProgramOptimization>
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<CharacterSet>Unicode</CharacterSet>
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</PropertyGroup>
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<Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
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<ImportGroup Label="ExtensionSettings">
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</ImportGroup>
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<ImportGroup Label="PropertySheets" Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
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<Import Project="$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props" Condition="exists('$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props')" Label="LocalAppDataPlatform" />
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</ImportGroup>
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<ImportGroup Label="PropertySheets" Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
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<Import Project="$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props" Condition="exists('$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props')" Label="LocalAppDataPlatform" />
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</ImportGroup>
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<PropertyGroup Label="UserMacros" />
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<PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
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<LinkIncremental>true</LinkIncremental>
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<OutDir>..\..\bin</OutDir>
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</PropertyGroup>
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<PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
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<LinkIncremental>false</LinkIncremental>
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<OutDir>..\..\bin</OutDir>
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</PropertyGroup>
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<ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
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<ClCompile>
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<PrecompiledHeader>
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</PrecompiledHeader>
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<WarningLevel>Level3</WarningLevel>
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<Optimization>Disabled</Optimization>
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<PreprocessorDefinitions>WIN32;_DEBUG;_CONSOLE;_LIB;%(PreprocessorDefinitions)</PreprocessorDefinitions>
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<SDLCheck>true</SDLCheck>
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<AdditionalIncludeDirectories>..\..\EXTERNAL\OpenCV\include</AdditionalIncludeDirectories>
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</ClCompile>
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<Link>
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<SubSystem>Console</SubSystem>
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<GenerateDebugInformation>true</GenerateDebugInformation>
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<AdditionalLibraryDirectories>..\..\EXTERNAL\OpenCV\lib</AdditionalLibraryDirectories>
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</Link>
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</ItemDefinitionGroup>
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<ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
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<ClCompile>
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<WarningLevel>Level3</WarningLevel>
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<PrecompiledHeader>
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</PrecompiledHeader>
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<Optimization>MaxSpeed</Optimization>
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<FunctionLevelLinking>true</FunctionLevelLinking>
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<IntrinsicFunctions>true</IntrinsicFunctions>
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<PreprocessorDefinitions>WIN32;NDEBUG;_CONSOLE;_LIB;%(PreprocessorDefinitions)</PreprocessorDefinitions>
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<SDLCheck>true</SDLCheck>
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<AdditionalIncludeDirectories>..\..\EXTERNAL\OpenCV\include</AdditionalIncludeDirectories>
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</ClCompile>
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<Link>
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<SubSystem>Console</SubSystem>
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<GenerateDebugInformation>true</GenerateDebugInformation>
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<EnableCOMDATFolding>true</EnableCOMDATFolding>
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<OptimizeReferences>true</OptimizeReferences>
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<AdditionalLibraryDirectories>..\..\EXTERNAL\OpenCV\lib</AdditionalLibraryDirectories>
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</Link>
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</ItemDefinitionGroup>
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<ItemGroup>
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<ClCompile Include="..\..\src\ransac_line.cpp" />
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</ItemGroup>
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<Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
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<ImportGroup Label="ExtensionTargets">
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</ImportGroup>
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</Project>

‎msvs/ransac_line/ransac_line.vcxproj.user‎

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<?xml version="1.0" encoding="utf-8"?>
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<Project ToolsVersion="12.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
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<PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
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<LocalDebuggerWorkingDirectory>$(OutDir)</LocalDebuggerWorkingDirectory>
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<DebuggerFlavor>WindowsLocalDebugger</DebuggerFlavor>
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</PropertyGroup>
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<PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
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<LocalDebuggerWorkingDirectory>$(OutDir)</LocalDebuggerWorkingDirectory>
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<DebuggerFlavor>WindowsLocalDebugger</DebuggerFlavor>
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</PropertyGroup>
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</Project>

‎src/ransac_line.cpp‎

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#include "opencv_all.hpp"
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#define CONVERT_LINE(line) (cv::Vec3d(line(0), -line(1), -line(0) * line(2) + line(1) * line(3)))
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int main(void)
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{
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int ransac_trial = 50;
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double ransac_thresh = 3.0;
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int ransac_n_sample = 2;
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int sim_n_data = 1000;
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double sim_inlier_ratio = 0.5, sim_inlier_noise = 1.0;
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cv::Vec3d truth(1.0 / sqrt(2.0), 1.0 / sqrt(2.0), -240.0); // The line model: a*x + b*y + c = 0
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// Generate data
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std::vector<cv::Point2d> data;
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cv::RNG rng;
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for (int i = 0; i < sim_n_data; i++)
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{
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if (rng.uniform(0.0, 1.0) < sim_inlier_ratio)
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{
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double x = rng.uniform(0.0, 480.0);
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double y = (truth(0) * x + truth(2)) / -truth(1);
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x += rng.gaussian(sim_inlier_noise);
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y += rng.gaussian(sim_inlier_noise);
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data.push_back(cv::Point2d(x, y)); // Inlier
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}
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else data.push_back(cv::Point2d(rng.uniform(0.0, 640.0), rng.uniform(0.0, 480.0))); // Outlier
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}
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// Estimate a line using RANSAC
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int best_score = -1;
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cv::Vec3d best_line;
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for (int i = 0; i < ransac_trial; i++)
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{
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// Step 1: Hypothesis generation
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std::vector<cv::Point2d> sample;
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for (int j = 1; j < ransac_n_sample; j++)
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{
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int index = rng.uniform(0, data.size());
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sample.push_back(data[index]);
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}
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cv::Vec4d vvxy;
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cv::fitLine(sample, vvxy, CV_DIST_L2, 0, 0.01, 0.01);
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cv::Vec3d line = CONVERT_LINE(vvxy);
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// Step 2: Hypothesis evaluation
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int score = 0;
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for (size_t j = 0; j < data.size(); j++)
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{
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double error = fabs(line(0) * data[j].x + line(1) * data[j].y + line(2));
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if (error < ransac_thresh) score++;
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}
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if (score > best_score)
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{
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best_score = score;
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best_line = line;
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}
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}
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// Estimate a line using least-squares method (for reference)
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cv::Vec4d vvxy;
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cv::fitLine(data, vvxy, CV_DIST_L2, 0, 0.01, 0.01);
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cv::Vec3d lsm_line = CONVERT_LINE(vvxy);
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// Display estimates
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printf("* The Truth: %.3f, %.3f, %.3f\n", truth(0), truth(1), truth(2));
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printf("* Estimate (RANSAC): %.3f, %.3f, %.3f (Score: %d)\n", best_line(0), best_line(1), best_line(2), best_score);
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printf("* Estimate (LSM): %.3f, %.3f, %.3f\n", lsm_line(0), lsm_line(1), lsm_line(2));
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return 0;
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}

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