StereoBM:opencv计算视差

0.前言
视差与深度的关系戳这里。在opencv里应该有三种求视差的方法和一些问题集锦，可参考：http://blog.csdn.net/chenyusiyuan/article/details/5967291/
1.代码

void saveDisp(const char* filename, Mat mat);int main(){    char* filename = "../disparity_value.txt";    Mat left = imread("../image/left_199.png",CV_LOAD_IMAGE_GRAYSCALE);    Mat right = imread("../image/right_199.png",CV_LOAD_IMAGE_GRAYSCALE);    double t = (double)getTickCount();    Mat disp;    StereoBM bm;      CvStereoBMState *BMState = cvCreateStereoBMState();    bm.state->SADWindowSize = 15;      bm.state->minDisparity = 0;      bm.state->numberOfDisparities = 80;      bm.state->textureThreshold = 10;      bm.state->uniquenessRatio = 8;      bm.state->speckleWindowSize = 10;      bm.state->speckleRange = 32;      bm.state->disp12MaxDiff = -1;      /*防止左侧黑边*/    copyMakeBorder(left, left, 0, 0, 80, 0, IPL_BORDER_REPLICATE);      copyMakeBorder(right, right, 0, 0, 80, 0, IPL_BORDER_REPLICATE);      bm.operator()(left,right,disp,CV_32F);    disp = disp.colRange(80, left.cols);      t = ((double)getTickCount() - t)/getTickFrequency();    cout<<"time:"<<t<<endl;    imshow("disp",disp);    saveDisp(filename,disp);    cvWaitKey(0);    return 0;}/**将视差保存到txt,用于MATLAB读取**/void saveDisp(const char* filename,  Mat mat)       {    int ih = mat.type();    //float disp = mat.at<float>(0,0);     FILE* fp = fopen(filename, "wt");    fprintf(fp, "%02d\n", mat.rows);    fprintf(fp, "%02d\n", mat.cols);    for(int y = 0; y < mat.rows; y++)    {        for(int x = 0; x < mat.cols; x++)        {            float disp = mat.at<float>(y, x); // 这里视差矩阵是CV_16S 格式的，故用 short 类型读取            fprintf(fp, "%f\n", disp); // 若视差矩阵是 CV_32F 格式，则用 float 类型读取        }    }    fclose(fp);}

相应的Matlab代码为：function img = txt2img(filename)data = importdata(filename);r = data(1);    % 行数c = data(2);    % 列数disp = data(3:end); % 视差vmin = min(disp);vmax = max(disp);disp = reshape(disp, [c,r])'; % 将列向量形式的 disp 重构为 矩阵形式%  OpenCV 是行扫描存储图像，Matlab 是列扫描存储图像%  故对 disp 的重新排列是首先变成 c 行 r 列的矩阵，然后再转置回 r 行 c 列img = uint8( 255 * ( disp - vmin ) / ( vmax - vmin ) );mesh(disp);set(gca,'YDir','reverse');  % 通过 mesh 方式绘图时，需倒置 Y 轴方向axis tight; % 使坐标轴显示范围与数据范围相贴合，去除空白显示区