学习 opencv 自带示例 stereo_calib（立体相机标定）

学习 opencv 自带示例 stereo_calib（立体相机标定）

准备

首先，需要编译 opencv 自带示例，可以参考之前的博客记录：
cmake+windows 编译 opencv 自带示例.

调试示例代码

目标工程

确定输入参数类型

/// 参数：
/// @ w：棋盘格（圆形）标定板的长边角点数目，对于 12x9 的棋盘格，w = 11
/// @ h：棋盘格（圆形）标定板的短边角点数目，对于 12x9 的棋盘格，h = 8
/// @ s：棋盘格方格尺寸，单位 cm
/// @ nr：no rectified: 如果加上这个参数，就不会显示矫正后的图像
/// @ help：命令行执行帮助提示
/// @ @input：保存标定图像集路径的 .xml 文件

cv::CommandLineParser parser(argc, argv, "{w|9|}{h|6|}{s|1.0|}{nr||}{help||}{@input|stereo_calib.xml|}");
if (parser.has("help"))
    return print_help();
showRectified = !parser.has("nr");
imagelistfn = samples::findFile(parser.get<string>("@input"));
boardSize.width = parser.get<int>("w");
boardSize.height = parser.get<int>("h");
float squareSize = parser.get<float>("s");

调试模式（debug）输入参数

右键此项目，点击属性选项，进入项目的属性页面，在调试 --> 命令参数栏中输入参数，我的标定板尺寸为 12x9 （角点尺寸 11x8）, 1.5cm。

标定图像集路径 .xml 文件地址（如上图）&格式（如下）。
stereo_calib.xml（部分文件）

<opencv_storage>
<imagelist>
"D:\M_MindVisionSDK_Clone\common_stereo_0702\common\build\calibration\image_pair\left_1.png"
"D:\M_MindVisionSDK_Clone\common_stereo_0702\common\build\calibration\image_pair\right_1.png"
"D:\M_MindVisionSDK_Clone\common_stereo_0702\common\build\calibration\image_pair\left_2.png"
"D:\M_MindVisionSDK_Clone\common_stereo_0702\common\build\calibration\image_pair\right_2.png"
"D:\M_MindVisionSDK_Clone\common_stereo_0702\common\build\calibration\image_pair\left_3.png"
"D:\M_MindVisionSDK_Clone\common_stereo_0702\common\build\calibration\image_pair\right_3.png"
"D:\M_MindVisionSDK_Clone\common_stereo_0702\common\build\calibration\image_pair\left_4.png"
"D:\M_MindVisionSDK_Clone\common_stereo_0702\common\build\calibration\image_pair\right_4.png"
...
...
...
"D:\M_MindVisionSDK_Clone\common_stereo_0702\common\build\calibration\image_pair\left_48.png"
"D:\M_MindVisionSDK_Clone\common_stereo_0702\common\build\calibration\image_pair\right_48.png"
"D:\M_MindVisionSDK_Clone\common_stereo_0702\common\build\calibration\image_pair\left_49.png"
"D:\M_MindVisionSDK_Clone\common_stereo_0702\common\build\calibration\image_pair\right_49.png"
imagelist>
opencv_storage>

F5 调试

图像的分辨率为1280x1024，一共 49 对（98张）图片，调试过程执行时间大约在 20+ 分钟左右（i5-9400F）。
标定开始（47对图像符合要求（找到角点））：

程序执行完毕（输出项目）

stereo_calib.cpp 执行完毕后会在命令行中显示输出，如果在程序执行前没有输入nr参数，此时就会显示每一对矫正后标定图像（包含裁剪区域，水平线）；在stereo_calib.cpp源文件所在目录，也会生成内参（intrinsic.yml）与外参（extrinsic.yml） 文件。

命令行输出

矫正图像

内外参程序默认存储地址

内参 intrinsic.yml

%YAML:1.0
---
M1: !!opencv-matrix
   rows: 3
   cols: 3
   dt: d
   data: [ 1.3241615532180620e+03, 0., 6.3819839672280261e+02, 0.,
       1.3248893276176391e+03, 5.1955679264247931e+02, 0., 0., 1. ]
D1: !!opencv-matrix
   rows: 1
   cols: 14
   dt: d
   data: [ -1.1636352792431695e-01, 2.8974617123762275e-01, 0., 0., 0.,
       0., 0., 1.2908722457060287e-01, 0., 0., 0., 0., 0., 0. ]
M2: !!opencv-matrix
   rows: 3
   cols: 3
   dt: d
   data: [ 1.3241615532180620e+03, 0., 6.3481565514416604e+02, 0.,
       1.3248893276176391e+03, 5.1084131542728164e+02, 0., 0., 1. ]
D2: !!opencv-matrix
   rows: 1
   cols: 14
   dt: d
   data: [ -1.0253422568346042e-01, 1.8838231393096699e-01, 0., 0., 0.,
       0., 0., -3.7932170237531426e-02, 0., 0., 0., 0., 0., 0. ]

外参 extrinsic.yml

%YAML:1.0
---
R: !!opencv-matrix
   rows: 3
   cols: 3
   dt: d
   data: [ 9.9999962469823134e-01, -8.6625827227159650e-04,
       -1.4142211807947691e-05, 8.6626849570826839e-04,
       9.9999935124684680e-01, 7.3965179573864872e-04,
       1.3501473146517586e-05, -7.3966376909856987e-04,
       9.9999972635757206e-01 ]
T: !!opencv-matrix
   rows: 3
   cols: 1
   dt: d
   data: [ -7.9332505690605970e+00, -1.7537722400808173e-02,
       -5.2447786996653978e-01 ]
R1: !!opencv-matrix
   rows: 3
   cols: 3
   dt: d
   data: [ 9.9782178211702999e-01, 1.2926754401776212e-03,
       6.5954682343262627e-02, -1.3199419700206951e-03,
       9.9999906048566101e-01, 3.6983914196800176e-04,
       -6.5954142295917270e-02, -4.5608990507940109e-04,
       9.9782255090572503e-01 ]
R2: !!opencv-matrix
   rows: 3
   cols: 3
   dt: d
   data: [ 9.9781935509686992e-01, 2.2058396748603540e-03,
       6.5967180214069804e-02, -2.1862041633003604e-03,
       9.9999754186115819e-01, -3.6984185448794930e-04,
       -6.5967833869417944e-02, 2.2481763670781029e-04,
       9.9782172473423680e-01 ]
P1: !!opencv-matrix
   rows: 3
   cols: 4
   dt: d
   data: [ 1.2570131053880084e+03, 0., 5.2801861572265625e+02, 0., 0.,
       1.2570131053880084e+03, 5.1521139144897461e+02, 0., 0., 0., 1.,
       0. ]
P2: !!opencv-matrix
   rows: 3
   cols: 4
   dt: d
   data: [ 1.2570131053880084e+03, 0., 5.2801861572265625e+02,
       -9.9939932841530499e+03, 0., 1.2570131053880084e+03,
       5.1521139144897461e+02, 0., 0., 0., 1., 0. ]
Q: !!opencv-matrix
   rows: 4
   cols: 4
   dt: d
   data: [ 1., 0., 0., -5.2801861572265625e+02, 0., 1., 0.,
       -5.1521139144897461e+02, 0., 0., 0., 1.2570131053880084e+03, 0.,
       0., 1.2577686112529091e-01, 0. ]

内外参数据说明

内参 intrinsic.yml

M1: cameraMatrix1 First camera matrix. （相机1矩阵）
D1: distCoeffs1 First camera distortion parameters.（distortion coefficient，相机1畸变系数）
M2: cameraMatrix2 Second camera matrix.（相机2矩阵）
D2: distCoeffs2 Second camera distortion parameters.（相机2畸变系数）

来源函数

/// @overload
CV_EXPORTS_W double stereoCalibrate( InputArrayOfArrays objectPoints,
                                     InputArrayOfArrays imagePoints1, InputArrayOfArrays imagePoints2,
                                     InputOutputArray cameraMatrix1, InputOutputArray distCoeffs1,
                                     InputOutputArray cameraMatrix2, InputOutputArray distCoeffs2,
                                     Size imageSize, OutputArray R,OutputArray T, OutputArray E, OutputArray F,
                                     int flags = CALIB_FIX_INTRINSIC,
                                     TermCriteria criteria = TermCriteria(TermCriteria::COUNT+TermCriteria::EPS, 30, 1e-6) );

外参 extrinsic.yml

R: @param R Rotation matrix between the coordinate systems of the first and the second cameras.（两相机坐标系的旋转矩阵）
T: @param T Translation vector between coordinate systems of the cameras.（两相机坐标系的平移向量）
R1: @param R1 Output 3x3 rectification transform (rotation matrix) for the first camera.（相机1的3x3整流变换（旋转矩阵））
R2: @param R2 Output 3x3 rectification transform (rotation matrix) for the second camera.（相机2的3x3整流变换（旋转矩阵））
P1: @param P1 Output 3x4 projection matrix in the new (rectified) coordinate systems for the first camera.（相机1对于新坐标系的（调整后的）投影矩阵）
P2: @param P2 Output 3x4 projection matrix in the new (rectified) coordinate systems for the second camera.（相机2对于新坐标系的（调整后的）投影矩阵）
Q: @param Q Output 4x4 disparity-to-depth mapping matrix (see reprojectImageTo3D ).（4X4视差 到 深度映射矩阵）

来源函数

CV_EXPORTS_W void stereoRectify( InputArray cameraMatrix1, InputArray distCoeffs1,
                                 InputArray cameraMatrix2, InputArray distCoeffs2,
                                 Size imageSize, InputArray R, InputArray T,
                                 OutputArray R1, OutputArray R2,
                                 OutputArray P1, OutputArray P2,
                                 OutputArray Q, int flags = CALIB_ZERO_DISPARITY,
                                 double alpha = -1, Size newImageSize = Size(),
                                 CV_OUT Rect* validPixROI1 = 0, CV_OUT Rect* validPixROI2 = 0 );

学习（TODO）

参考

1. 链接: cmake+windows 编译 opencv 自带示例.
2. 链接: link.