topic Showing Depth Data through a cv::Mat in Software Archive

Showing Depth Data through a cv::Mat

Marios_B_ — Fri, 15 May 2015 10:22:46 GMT

Hi guys!

I want to show to the user a Depth Image mapped to Color.I want to do this by using a cv::Mat.

I used the projection->CreateDepthImageMappedToColor(PXCImage *depth, PXCImage *color);

p and I managed to pass the pxcimage data to a cv::Mat MappedDepthMat(480,640,CV_16UC1); by using the following function:

void CopyDepthImageMappedToColor_ToMat(PXCImage *ColorImage,PXCImage *DepthImage,PXCImage::ImageData &data,cv::Mat &MappedDepthMat)
{
	PXCImage* mapped=projection->CreateDepthImageMappedToColor(DepthImage,ColorImage);
	pxcStatus sts=mapped->AcquireAccess(PXCImage::ACCESS_READ,&data);
	if(sts==PXC_STATUS_NO_ERROR )
	{
		memcpy(MappedDepthMat.data,data.planes[0],sizeof(unsigned short) * 640 * 480);
		MappedDepthMat=MappedDepthMat*255;
		mapped->ReleaseAccess(&data);
	}

}

You can see that I multiply each element by 255.If I don't do this,then I get a black screen because of the Mat.The original values of MappedDepthMat before I multiply by 255 give me the distance in mm,correct? What is the maximum value?Can I somehow normalize the whole thing and have max depth=1 and min depth=0?

What is the original range?When I call the above mentioned function what is the max value of pixel?Can I somehow change the maximum value and still get the required result?

At the end of the day,I want to have a Mat with a range of 0-1 but with float values in between.I need this to match with the opengl's z-buffer values.

Could you change

Xusheng_L_Intel — Tue, 19 May 2015 22:01:02 GMT

Could you change

pxcStatus sts=mapped->AcquireAccess(PXCImage::ACCESS_READ,&data);

pxcStatus sts=mapped->AcquireAccess(PXCImage::ACCESS_READ,PXCImage::PIXEL_FORMAT_DEPTH_F32, &data);

and let me know if you still have such issue. Thanks!

Hi, This my code, it

x_c_ — Fri, 17 Jul 2015 03:34:14 GMT

Hi, This my code, it succeeeded, and maybe it will help you.

Mat depthimage8;
depthimage8.create(480,640,CV_8UC1);

PXCImage::ImageData data_depth; unsigned short *depth_data;

sample->depth->AcquireAccess(PXCImage::ACCESS_READ,PXCImage::PIXEL_FORMAT_DEPTH, &data_depth);
                   depth_data = (unsigned short*)data_depth.planes[0];
                   unsigned char cVal;
                   for(int y=0; y<H; y++)
                   {
                       for(int x=0; x<W; x++)
                       {
                           if(depth_data[y*W+x] > fMaxValue)   //fMaxValue = 1000
                               depth_data[y*W+x] = fMaxValue;
                           cVal = (unsigned char)((1.0*depth_data[y*W+x])/fMaxValue*255);
                           if(cVal!=0)
                               cVal = 255 - cVal;
                           depthimage8.at<unsigned char>(y,x) = cVal;
                       }
                   }