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2018-04-04 03:47:41 -0500 marked best answer How to create a empty rect?

How do i instantiate a empty Rect?

Rect ROI = NULL doesn't work...

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2016-03-26 12:28:37 -0500 commented answer How to use cv::StereoMatcher in c++

New error message : Allocating an object of abstract class type cv::StereoMatcher

`cv::Ptr<cv::StereoMatcher> match = cv::makePtr<cv::StereoMatcher>();`
2016-03-26 12:14:08 -0500 commented answer How to use cv::StereoMatcher in c++

I am getting this error variable type cv::StereoMatcher is an abstract class

2016-03-26 12:05:40 -0500 commented question How to use cv::StereoMatcher in c++

How would you do so? cv::StereoMatcher map won't run as stereoMatcher is an abstract class.

2016-03-26 12:00:22 -0500 asked a question How to use cv::StereoMatcher in c++

I struggling a bit understanding how i should apply StereoMatcher to create a simple disparity map?..

From the Api it seems simple but, but this simple piece of code does result in bad_memory access error.

What is going wrong?

#include <iostream>
#include <opencv2/calib3d/calib3d.hpp>
#include <opencv2/opencv.hpp>
#include <opencv2/core.hpp>
#include <opencv2/features2d.hpp>
#include <opencv2/core/affine.hpp>

int main(int argc, const    char * argv[]) {
    // insert code here...
    std::cout << "Hello, World!\n";
    std::cout << CV_VERSION << std::endl;

    cv::Mat left = cv::imread("../left.png");
    cv::Mat right = cv::imread("../right.png");
    cv::Mat disparity_out;
    cv::StereoMatcher* map;
    map->compute(left, right, disparity_out);

    return 0;
2016-03-26 06:26:44 -0500 commented question which library has to be included for cv::StereoVar

I am using 3.1.0

2016-03-26 06:19:25 -0500 asked a question which library has to be included for cv::StereoVar

What library should I include to make use of StereoVar

The Api seems to refer to contrib, but the library won't compile due to a simple error (So i think) as missing namespace?..

Is it intended that the user has to change the library itself, or is it a bug?

2016-03-24 03:58:31 -0500 asked a question stereo matching with already calibrated images?

Is it possible using openCV to compute a disparity map of a stereo images, which has already been rectified by the camera itself.

All the methods i can find here, want me to pass the camera intrinsic and extrinsic parameter, which i don't get (unless it want to calibrate the images).

2016-03-22 12:50:05 -0500 commented answer fastest way to detect a red ball?

I Wont know the distance for sure as the size of Ball of the image is not known.. I am using stereo vision

2016-03-22 11:15:43 -0500 asked a question fastest way to detect a red ball?

I at moment trying to implement a simple an robust way of detecting an red ball.

I've converted into HSV and filtered using inRange(..), such that the red ball is clear and some other noise.

But what approach would be appropriate to detect the ball?

findContour and Hough seems a bit overkill computation wise, but what other alternatives do i have. I have to detect the position of the ball at all time, so the speed of the algorithm has to be appropriate for tracking.

what do you suggest?

2016-03-20 15:01:56 -0500 commented question Save two different images displayed at separate imshow?

exactly .... :|

2016-03-20 14:27:43 -0500 asked a question Save two different images displayed at separate imshow?

How do i store two different images at the same time, when a key is pressed?

2016-03-20 02:55:07 -0500 asked a question Extract feature of an red object from an stereo image?

I am looking for an easy method to implement stereopsis, such that i can extract the depth information of an object from a preprocessed input stereo image. Does openCV not provide with some form of function which allow to extract the depth and so on?

All the method which seem available in openCv perform dense stereopsis, which computation wise for me seems to be a bit overkill..

2016-02-03 09:34:08 -0500 marked best answer Create a mat ROI for each contour blob?

How would one create multiple ROI Mat based on a

vector <vector < point >> contours.

I have this function

vector<vector<Point> > MarkCountours(Mat binaryImg)
    vector<vector<Point> > contours;
    Mat test = binaryImg.clone();
    vector<Vec4i> hierarchy;
    RNG rng(12345);
    findContours( test, contours, hierarchy, CV_RETR_TREE, CV_CHAIN_APPROX_SIMPLE, Point(0, 0) );
    vector<vector<Point> > contours_poly( contours.size() );
    vector<Rect> boundRect( contours.size() );
    vector<Point2f>center( contours.size() );
    vector<float>radius( contours.size() );
    for( int i = 0; i < contours.size(); i++ )
        approxPolyDP( Mat(contours[i]), contours_poly[i], 3, true );
        boundRect[i] = boundingRect( Mat(contours_poly[i]) );
    Mat drawing = Mat::zeros( binaryImg.size(), CV_8UC3 );
    for( int i = 0; i< contours.size(); i++ )
        Scalar color = Scalar(255,0,255);
        drawContours( drawing, contours_poly, i, color, 1, 8, vector<Vec4i>(), 0, Point() );
        rectangle( drawing, boundRect[i].tl(), boundRect[i].br(), color, 2, 8, 0 );

    return contours;

This draws rectangle on the binary image, based on contours, but how do i based on those countours create multiple Mat which consist of ROI where the contours are in interest..

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2015-12-13 01:54:32 -0500 commented question error when trying to convert rgb to hsv...

but again.. what type am i looking for.. couldn't i just convert it to certain type or something like that?

2015-12-13 01:43:53 -0500 commented question error when trying to convert rgb to hsv...

oh... yeah.. it looks like i have multiple versions.. but yeah, i need to use the one for 2.4.8...

What types does is support?

2015-12-12 18:10:56 -0500 asked a question error when trying to convert rgb to hsv...

I am the moment trying to convert a rgb to hsv, which seems impossible.. I thought i might have been due the Mat being empty.. but thats not the case...

I get this error message.

/build/buildd/opencv-2.4.8+dfsg1/modules/imgproc/src/color.cpp:3642: error: (-215) depth == CV_8U || depth == CV_16U || depth == CV_32F in function cvtColor

for these lines of code..

Point find(Mat frame)

    Mat imgOriginal = frame.clone();
    Mat imgHSV = frame.clone();

    if (frame.empty())
        cout << "Empty...';
        exit -1;

    cvtColor(imgOriginal, imgHSV, COLOR_BGR2HSV); //Convert the captured frame from BGR to HSV

what could be going wrong here???