有谁知道这一段代码的含义？

void detectDistance(cv::Mat& pointCloud)
{
if (pointCloud.empty())
{
return;
}

vector<cv::Mat> xyzSet;
split(pointCloud, xyzSet);
cv::Mat depth;
xyzSet[2].copyTo(depth);


double maxVal = 0, minVal = 0;
cv::Mat depthThresh = cv::Mat::zeros(depth.rows, depth.cols, CV_8UC1);
cv::minMaxLoc(depth, &minVal, &maxVal);
double thrVal = minVal * 1.5;
threshold(depth, depthThresh, thrVal, 255, CV_THRESH_BINARY_INV);
depthThresh.convertTo(depthThresh, CV_8UC1);
//imageDenoising(depthThresh, 3);

double  distance = depth.at<float>(pic_info[0], pic_info[1]);
cout << "distance:" << distance << endl;

}

http://blog.csdn.net/hysteric314/article/details/50456570