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2013-07-24 04:43:45 -0500 asked a question Drawing onto a transparent Mat


I'm doing a colour tracking application that draws a line following that colour. You are probably quite familiar with the code, I followed an online tutorial :

//track yellow 
  IplImage* GetThresholdedImage1(IplImage* img)
// Convert the image into an HSV image

 IplImage* imgHSV = cvCreateImage(cvGetSize(img), 8, 3);
cvCvtColor(img, imgHSV, CV_BGR2HSV);
// Create new image to hold thresholded image
IplImage* imgThreshed = cvCreateImage(cvGetSize(img), 8, 1);
 cvInRangeS(imgHSV, cvScalar(20, 100, 100), cvScalar(30, 255, 255), imgThreshed); // apply threshold original
return imgThreshed;


IplImage *frame=0;
frame =cvQueryFrame(capture);
IplImage* imgYellowThresh1 = GetThresholdedImage1(frame);
//scribble lines on to frame 
    imgScribble =cvCreateImage(cvGetSize(frame),8,3);

So this draws a yellow line on the video from my webcam. What I want is to replace the video with a transparent background. Does anyone know how to create a transparent Mat and then draw onto it instead of the frame. I tried to draw on to the canvas but this doesn't seem to be working :

 IplImage* imgYellowThresh1 = GetThresholdedImage1(canvas);

Any advice is greatly appreciated. Thanks!

2013-07-16 10:59:46 -0500 commented question ld: library not found for -lopencv_calib3d.2.4.3

Okay I'll look into it. Thanks!

2013-07-16 08:11:07 -0500 commented question ld: library not found for -lopencv_calib3d.2.4.3

Sorry by linker settings, do you mean changing the header search path?

2013-07-16 07:28:31 -0500 commented question ld: library not found for -lopencv_calib3d.2.4.3

I have libopencv_calib3d.2.4.3.dylib in my project so I'm not sure why it is missing

2013-07-16 03:47:29 -0500 asked a question ld: library not found for -lopencv_calib3d.2.4.3


I'm working on a mac 10.7.5 and xcode 4.6.2. I've followed a tutorial to install opencv and cmake.

In terminal :

 mkdir build
cd build
make -j8
sudo make install

I've opened up Xcode and added the .dylib files from /usr/local/lib changed the header files

Then I wrote an include to test:

#include <opencv2/opencv.hpp>
#include <opencv2/highgui/highgui.hpp>

The error I'm getting is :

ld: library not found for -lopencv_calib3d.2.4.3
collect2: ld returned 1 exit status
Command /Applications/ failed with exit code 1

Can anyone give me a hand fixing this? Would be greatly appreciated!