c++ - Convertion Between cv::Mat and XnDepthPixel* -

i working openni 1.5.4.0 , opencv 2.4.5, plus qt visualization purpose (only rgb images). basically, retrieving depth , rgb frames kinect , store them on hard drive, using conversion:

/* depth conversion */  cv::mat depth = cv::mat(2, sizes, cv_16uc1, (void*) pdepthmap); //xndepthpixel *pdepthmap   /* rgb conversion */  ///image qimage* , pimagemap xnuint8*  for(int = 0; < height; ++i) {     (unsigned y = 0; y < height; ++y)     {        uchar *imageptr = (*image).scanline(y);        (unsigned x=0; x < width; ++x)        {           imageptr[0] = pimagemap[2];           imageptr[1] = pimagemap[1];           imageptr[2] = pimagemap[0];           imageptr[3] = 0xff;           imageptr+=4;           pimagemap+=3;        }     } } 

now, want load images hard drive, in order compute 3d pointclouds post-processing computation. loading depth maps as:

depth_image = cv::imread(m_rgb_files.at(w).tostdstring(), cv_load_image_anydepth | cv_load_image_anycolor ); 

but applying formulas:

depth = depth_image.at<int>(j,i);  //depth_image stored 16bit p.z = (float)depth * 0.001f;    //converting millimeters meters p.x = (float)(i - m_params.center_x) * depth * m_params.focal_length; //focal_length read using openni function p.y = (float)(j - m_params.center_y) * depth * m_params.focal_length; 

the pointcloud obtained mess.

if "online" processing, using directly native xndepthpixel* data, result perfect, using formulas written before. can give me "hint" fault?

thanks in advance

edit: following resource, doesn't work me, because xndepthpixel contains real world data in millimeters

i think there possible problem here:

depth = depth_image.at<int>(j,i);  //depth_image stored 16bit 

if depth image is 16-bit, should be:

depth = depth_image.at<short>(j,i);  //depth_image stored 16bit 

because int 32-bits, not 16.