Converting Depth Image into open cv Mat format - c++

Question

I am using a PMD camera to capture depth image in the below format
struct DepthData
{
int version;
std::chrono::microseconds timeStamp;
uint16_t width;
uint16_t height;
Vector of uint_16 exposureTimes;
Vector of DepthPoint points; //!< array of points
};
Depth point structure looks like this
struct DepthPoint
{
float x; //!< X coordinate [meters]
float y; //!< Y coordinate [meters]
float z; //!< Z coordinate [meters]
float noise; //!< noise value [meters]
uint16_t grayValue; //!< 16-bit gray value
uint8_t depthConfidence; //!< value 0 = bad, 255 = good
};
And I am trying to convert it into opencv mat data structure. Below is the code.
But it is throwing an exception. Kindly help
const int imageSize = w * h;
Mat out = cv::Mat(h, w, CV_16UC3, Scalar(0, 0, 0));
const Scalar S;
for (int h = 0; h < out.rows; h++)
{
//printf("%" PRIu64 "\n", point.at(h).grayValue);
for (int w = 0; w < out.cols; w++)
{
//printf("%" PRIu64 "\n", point.at(h).grayValue);
out.at<cv::Vec3f>(h,w)[0] = point[w].x;
out.at<cv::Vec3f>(h, w)[1] = point[w].y;
out.at<cv::Vec3f>(h, w)[2] = point[w].z;
}
}
imwrite("E:/softwares/1.8.0.71/bin/depthImage1.png", out);

Answer 1

You seem to be doing a couple of things wrong.
You are creating an image of type CV_16UC3 which is a 3 channel 16 bit unsigned char image. Then in out.at<cv::Vec3f>(h,w)[0] you try to read part of it as a vector of 3 floats. You should probably create your image as a float image instead.
For further details please provide the exception. It will be easier to help.
UPD: If you just want a depth image, create an image like this:
Mat out = cv::Mat::zeros(h, w, CV_16UC1);
Then in every pixel:
out.at<uint16_t>(h, w) = depth_point.grayValue;