Attention: Answers.ros.org is deprecated as of August the 11th, 2023. Please visit robotics.stackexchange.com to ask a new question. This site will remain online in read-only mode during the transition and into the foreseeable future. Selected questions and answers have been migrated, and redirects have been put in place to direct users to the corresponding questions on Robotics Stack Exchange. Additional details are available here.

Convert cv_bridge Image to cv::Mat image

asked 2016-02-03 11:07:17 -0500

user23fj239
748 ●26 ●37 ●47

I would like to have a pure OpenCV version cv::Mat of the Image on which I can do further modifications. I tried cv_ptr->dImg; but it outputs errors. So far I have

 void imageCb(const sensor_msgs::ImageConstPtr& msg)
   {
    cv_bridge::CvImagePtr cv_ptr;
    try
    {
      cv_ptr = cv_bridge::toCvCopy(msg, sensor_msgs::image_encodings::TYPE_16UC1);
    }
    catch (cv_bridge::Exception& e)
    {
      ROS_ERROR("cv_bridge exception: %s", e.what());
      return;
    }

    // Draw an example circle on the video stream
    //if (cv_ptr->image.rows > 60 && cv_ptr->image.cols > 60)
     // cv::circle(cv_ptr->image, cv::Point(px, py), 10, CV_RGB(255,0,0));
        cv::Mat dImg;

edit retag flag offensive close merge delete

add a comment

1 Answer

Sort by » oldest newest most voted

answered 2016-02-03 11:57:17 -0500

user23fj239
748 ●26 ●37 ●47

I guess I figured it out. Did I make any mistakes?

cv::Mat dImg =  cv_ptr->image;
     double min = 0;
     double max = 1000;
cv::Mat img_scaled_8u;
cv::Mat(cv_ptr->image-min).convertTo(img_scaled_8u, CV_8UC1, 255. / (max - min));
cv::cvtColor(img_scaled_8u, dImg, CV_GRAY2RGB);
//if (cv_ptr->image.rows > 60 && cv_ptr->image.cols > 60)
//cv::circle(dImg, cv::Point(px, py), 10, CV_RGB(255,0,0));
// Update GUI Window
cv::imshow(OPENCV_WINDOW, dImg);
cv::waitKey(3);

edit flag offensive delete link

Comments

I only needed the part of converting cv_bridge image to Mat. It worked for me - thanks!

Gushu ( 2018-05-24 07:13:38 -0500 )edit

add a comment

Question Tools

1 follower

Stats

Asked: 2016-02-03 11:07:17 -0500

Seen: 7,068 times

Last updated: Feb 03 '16

Convert cv_bridge Image to cv::Mat image edit

1 Answer

Comments

Question Tools

Stats

Related questions

Convert cv_bridge Image to cv::Mat image