1200字范文 > 基于Matlab-采用张正友标定法对双目相机进行标定

基于Matlab-采用张正友标定法对双目相机进行标定

时间：2019-04-03 11:56:27

一、工作环境

操作系统：Win10

开发环境: Matlab b（需要摄像头驱动包）

相机：USB双目相机，支持UVC标准协议

1、安装摄像头驱动包（OS Generic Video Interface）

插上摄像头，在Matlab命令行窗口中输入如命令(webcam)，如果出现如下界面，说明安装成功：

2、测试摄像头

执行clear ans，清除刚才执行webcam得到的结果，断开摄像头连接。（注：由于上一步执行了webcam指令，Matlab默认自动连接了摄像头，这里先clear ans清除连接的摄像头）

执行webcam(1)或者webcam(‘3D_SHOP’)，（注：这里的‘3D_SHOP’是从ans中的name元素中得到的，如果有多个摄像头，会存在多个名称，可指定连接哪一个名称）连接摄像头。

设置分分辨率

显示视频流

二、标定前的准备工作

1、设计GUI

在进行标定工作之前，我们需要先采集图像数据，为方便后续的图像采集工作，先设计一款简单的双目摄像头拍照GUI，如上图所示。打开Matlab的GUI设计APP。如下图所示。

1）设计界面

2）切换到代码界面

classdef M3 < matlab.apps.AppBase% Properties that correspond to app componentsproperties (Access = public)UIFigure matlab.ui.FigureGridLayout matlab.ui.container.GridLayoutcamLeftmatlab.ui.control.UIAxesstartCam matlab.ui.control.ButtonrecordCam matlab.ui.control.ButtoncloseCam matlab.ui.control.ButtoncamRight matlab.ui.control.UIAxessaveButton matlab.ui.control.Buttonendproperties (Access = private)endproperties (Access = public)cam % DescriptionreImage = 0imageLeft % DescriptionimageRight % DescriptioncamImage % DescriptionsaveUrl = '0'end% Callbacks that handle component eventsmethods (Access = private)% Button pushed function: startCamfunction startCamButtonPushed(app, event)app.cam=webcam(1)app.cam.Resolution = '2560x960'app.camImage = snapshot(app.cam)im=image(app.camLeft, zeros(size(app.camImage), 'uint8'))axis(app.camLeft, 'image')preview(app.cam, im)end% Button pushed function: closeCamfunction closeCamButtonPushed(app, event)delete(app)end% Button pushed function: recordCamfunction recordCamButtonPushed(app, event)app.camImage = snapshot(app.cam)im = image(app.camRight, app.camImage)axis(app.camRight, 'image')app.imageLeft = app.camImage(1:960, 1:1280, 1:3)app.imageRight = app.camImage(1:960, 1281:2560, 1:3)app.reImage = app.reImage + 1imwrite(app.imageLeft, sprintf('%s%s%d%s', app.saveUrl, '\left', app.reImage, '.bmp'))imwrite(app.imageRight, sprintf('%s%s%d%s', app.saveUrl, '\right', app.reImage, '.bmp'))end% Button pushed function: saveButtonfunction saveButtonPushed(app, event)app.saveUrl = uigetdir('\.')if(app.saveUrl ~= '0')app.recordCam.Enable = trueendendend% Component initializationmethods (Access = private)% Create UIFigure and componentsfunction createComponents(app)% Create UIFigure and hide until all components are createdapp.UIFigure = uifigure('Visible', 'off');app.UIFigure.Color = [0.9412 0.9412 0.9412];app.UIFigure.Position = [100 100 685 499];app.UIFigure.Name = 'UI Figure';app.UIFigure.Scrollable = 'on';% Create GridLayoutapp.GridLayout = uigridlayout(app.UIFigure);app.GridLayout.ColumnWidth = {'1.8x', 99.99, '1x', 44, 50.99, '1x', 99.99, '1.7x'};app.GridLayout.RowHeight = {'5.12x', '1x', 36};app.GridLayout.ColumnSpacing = 1.22318522135417;app.GridLayout.Padding = [1.22318522135417 10 1.22318522135417 10];% Create camLeftapp.camLeft = uiaxes(app.GridLayout);title(app.camLeft, 'Left')xlabel(app.camLeft, '')ylabel(app.camLeft, '')app.camLeft.XColor = [1 1 1];app.camLeft.XTick = [];app.camLeft.YColor = [1 1 1];app.camLeft.YTick = [];app.camLeft.ZColor = [1 1 1];app.camLeft.TitleFontWeight = 'bold';app.camLeft.Layout.Row = 1;app.camLeft.Layout.Column = [1 4];% Create startCamapp.startCam = uibutton(app.GridLayout, 'push');app.startCam.ButtonPushedFcn = createCallbackFcn(app, @startCamButtonPushed, true);app.startCam.HandleVisibility = 'off';app.startCam.BusyAction = 'cancel';app.startCam.IconAlignment = 'center';app.startCam.FontSize = 14;app.startCam.Layout.Row = 2;app.startCam.Layout.Column = 1;app.startCam.Text = '开始';% Create recordCamapp.recordCam = uibutton(app.GridLayout, 'push');app.recordCam.ButtonPushedFcn = createCallbackFcn(app, @recordCamButtonPushed, true);app.recordCam.HandleVisibility = 'off';app.recordCam.BusyAction = 'cancel';app.recordCam.IconAlignment = 'center';app.recordCam.FontSize = 15;app.recordCam.Enable = 'off';app.recordCam.Layout.Row = 2;app.recordCam.Layout.Column = 6;app.recordCam.Text = '拍照';% Create closeCamapp.closeCam = uibutton(app.GridLayout, 'push');app.closeCam.ButtonPushedFcn = createCallbackFcn(app, @closeCamButtonPushed, true);app.closeCam.HandleVisibility = 'off';app.closeCam.BusyAction = 'cancel';app.closeCam.IconAlignment = 'center';app.closeCam.FontSize = 15;app.closeCam.Layout.Row = 2;app.closeCam.Layout.Column = 8;app.closeCam.Text = '关闭';% Create camRightapp.camRight = uiaxes(app.GridLayout);title(app.camRight, 'Right')xlabel(app.camRight, '')ylabel(app.camRight, '')app.camRight.XColor = [1 1 1];app.camRight.XTick = [];app.camRight.YColor = [1 1 1];app.camRight.YTick = [];app.camRight.ZColor = [1 1 1];app.camRight.TitleFontWeight = 'bold';app.camRight.Layout.Row = 1;app.camRight.Layout.Column = [5 8];% Create saveButtonapp.saveButton = uibutton(app.GridLayout, 'push');app.saveButton.ButtonPushedFcn = createCallbackFcn(app, @saveButtonPushed, true);app.saveButton.IconAlignment = 'center';app.saveButton.FontSize = 14;app.saveButton.Layout.Row = 2;app.saveButton.Layout.Column = 3;app.saveButton.Text = '保存';% Show the figure after all components are createdapp.UIFigure.Visible = 'on';endend% App creation and deletionmethods (Access = public)% Construct appfunction app = M3% Create UIFigure and componentscreateComponents(app)% Register the app with App DesignerregisterApp(app, app.UIFigure)if nargout == 0clear appendend% Code that executes before app deletionfunction delete(app)% Delete UIFigure when app is deleteddelete(app.UIFigure)endendend

上图中，白色部分为我加入的代码，其他是由Matlab APP GUI生成代码。

3）GUI操作方法

开始：GUI连接摄像头

保存：选择图片将要保存的路径

拍照：拍照，保存照片

2、采用Matlab设计棋盘格

close all;clear all;clc;width=1024 ;%pattern的宽height=768;%pattern的高img_final=zeros(height,width);reinforceconner=0 ;%是否加强角点 row=10; %pattern中棋盘格的行数col=13 ; %pattern中棋盘格的列数length=45; %pattern中棋盘格的大小org_X=(height-row*length)/2; %pattern关于纵轴方向的位置，默认放在中间org_Y=(width-col*length)/2; %pattern关于横轴方向的位置，默认放在中间color1=1;color2=color1;img=zeros(row*length,col*length);for i=0:(row-1)color2=color1;for j=0:(col-1)if color2==1img(i*length+1:(i+1)*length-1,j*length+1:(j+1)*length-1)=color2;end%不加的话，可以注释掉%color2=~color2;endcolor1=~color1;endimg_final(org_X:org_X+row*length-1,org_Y:org_Y+col*length-1)=img;img_final=~img_final;figure;imshow(img_final); imwrite(img_final, 'cheesBoard.bmp','bmp');

引用自zhouyelihua/zhouyelihua/article/details/46674191

三、采集图像，对双目标机进行标定

stereoCameraCalibrator：Matlab双目相机标定工具箱

补充一个知识：

***重投影：***重投影也就是指的第二次投影。

其实第一次投影指的就是相机在拍照的时候三维空间点投影到图像上。

然后我们利用这些图像对一些特征点进行三角定位（triangulation），利用几何信息（对极几何）构建三角形来确定三维空间点的位置

最后利用我们计算得到的三维点的坐标（注意不是真实的）和我们计算得到的相机位姿（当然也不是真实的）进行第二次投影，也就是重投影。

**对极几何：极线几何约束是一种点对直线的约束，而不是点与点的约束，尽管如此，极线约束给出了对应点重要的约束条件，它将对应点匹配从整幅图像寻找压缩到在一条直线上寻找对应点。在立体视觉测量中，立体匹配（对应点的匹配）是一项关键技术，极线几何在其中起着重要作用。立体视觉系统中，有两个摄像机在不同角度拍摄物理空间中的一实体点，在两副图像上分别成有有两个成像点。立体匹配就是已知其中的一个成像点，在另一副图像上找出该成像点的对应点—极限搜索（高翔13.2讲）。极线几何约束是一种常用的匹配约束技术。（Mastering OpenCV with Practical Computer Vision Projects）