find_contours_nodelet.cpp
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34 
35 // https://github.com/Itseez/opencv/blob/2.4/samples/cpp/tutorial_code/ShapeDescriptors/findContours_Demo.cpp
42 #include <ros/ros.h>
43 #include "opencv_apps/nodelet.h"
46 #include <cv_bridge/cv_bridge.h>
48 
49 #include <opencv2/highgui/highgui.hpp>
50 #include <opencv2/imgproc/imgproc.hpp>
51 
52 #include <dynamic_reconfigure/server.h>
53 #include "opencv_apps/FindContoursConfig.h"
54 #include "opencv_apps/Contour.h"
55 #include "opencv_apps/ContourArray.h"
56 #include "opencv_apps/ContourArrayStamped.h"
57 
58 namespace opencv_apps
59 {
61 {
66 
68 
69  typedef opencv_apps::FindContoursConfig Config;
70  typedef dynamic_reconfigure::Server<Config> ReconfigureServer;
71  Config config_;
73 
77 
79 
80  std::string window_name_;
81  static bool need_config_update_;
82 
83  void reconfigureCallback(Config& new_config, uint32_t level)
84  {
85  config_ = new_config;
86  low_threshold_ = config_.canny_low_threshold;
87  }
88 
89  const std::string& frameWithDefault(const std::string& frame, const std::string& image_frame)
90  {
91  if (frame.empty())
92  return image_frame;
93  return frame;
94  }
95 
96  void imageCallbackWithInfo(const sensor_msgs::ImageConstPtr& msg, const sensor_msgs::CameraInfoConstPtr& cam_info)
97  {
98  doWork(msg, cam_info->header.frame_id);
99  }
100 
101  void imageCallback(const sensor_msgs::ImageConstPtr& msg)
102  {
103  doWork(msg, msg->header.frame_id);
104  }
105 
106  static void trackbarCallback(int /*unused*/, void* /*unused*/)
107  {
108  need_config_update_ = true;
109  }
110 
111  void doWork(const sensor_msgs::ImageConstPtr& msg, const std::string& input_frame_from_msg)
112  {
113  // Work on the image.
114  try
115  {
116  // Convert the image into something opencv can handle.
117  cv::Mat frame = cv_bridge::toCvShare(msg, sensor_msgs::image_encodings::BGR8)->image;
118 
119  // Messages
120  opencv_apps::ContourArrayStamped contours_msg;
121  contours_msg.header = msg->header;
122 
123  // Do the work
124  cv::Mat src_gray;
125 
127  if (frame.channels() > 1)
128  {
129  cv::cvtColor(frame, src_gray, cv::COLOR_RGB2GRAY);
130  }
131  else
132  {
133  src_gray = frame;
134  }
135  cv::GaussianBlur(src_gray, src_gray, cv::Size(3, 3), 0, 0, cv::BORDER_DEFAULT);
136 
138  if (debug_view_)
139  {
140  cv::namedWindow(window_name_, cv::WINDOW_AUTOSIZE);
141  }
142 
143  cv::Mat canny_output;
144  int max_thresh = 255;
145  std::vector<std::vector<cv::Point> > contours;
146  std::vector<cv::Vec4i> hierarchy;
147  cv::RNG rng(12345);
148 
150  cv::blur(src_gray, canny_output, cv::Size(3, 3));
151 
153  cv::Canny(canny_output, canny_output, low_threshold_, low_threshold_ * 2, 3);
154 
156  cv::findContours(canny_output, contours, hierarchy, CV_RETR_TREE, CV_CHAIN_APPROX_SIMPLE, cv::Point(0, 0));
157 
159  cv::Mat drawing = cv::Mat::zeros(canny_output.size(), CV_8UC3);
160  for (size_t i = 0; i < contours.size(); i++)
161  {
162  cv::Scalar color = cv::Scalar(rng.uniform(0, 255), rng.uniform(0, 255), rng.uniform(0, 255));
163  cv::drawContours(drawing, contours, (int)i, color, 2, 8, hierarchy, 0, cv::Point());
164 
165  opencv_apps::Contour contour_msg;
166  for (const cv::Point& j : contours[i])
167  {
168  opencv_apps::Point2D point_msg;
169  point_msg.x = j.x;
170  point_msg.y = j.y;
171  contour_msg.points.push_back(point_msg);
172  }
173  contours_msg.contours.push_back(contour_msg);
174  }
175 
177  if (debug_view_)
178  {
179  if (need_config_update_)
180  {
181  config_.canny_low_threshold = low_threshold_;
182  reconfigure_server_->updateConfig(config_);
183  need_config_update_ = false;
184  }
185  cv::createTrackbar("Canny thresh:", window_name_, &low_threshold_, max_thresh, trackbarCallback);
186 
187  cv::imshow(window_name_, drawing);
188  int c = cv::waitKey(1);
189  }
190 
191  // Publish the image.
192  sensor_msgs::Image::Ptr out_img =
194  img_pub_.publish(out_img);
195  msg_pub_.publish(contours_msg);
196  }
197  catch (cv::Exception& e)
198  {
199  NODELET_ERROR("Image processing error: %s %s %s %i", e.err.c_str(), e.func.c_str(), e.file.c_str(), e.line);
200  }
201 
202  prev_stamp_ = msg->header.stamp;
203  }
204 
205  void subscribe() // NOLINT(modernize-use-override)
206  {
207  NODELET_DEBUG("Subscribing to image topic.");
208  if (config_.use_camera_info)
209  cam_sub_ = it_->subscribeCamera("image", queue_size_, &FindContoursNodelet::imageCallbackWithInfo, this);
210  else
211  img_sub_ = it_->subscribe("image", queue_size_, &FindContoursNodelet::imageCallback, this);
212  }
213 
214  void unsubscribe() // NOLINT(modernize-use-override)
215  {
216  NODELET_DEBUG("Unsubscribing from image topic.");
217  img_sub_.shutdown();
218  cam_sub_.shutdown();
219  }
220 
221 public:
222  virtual void onInit() // NOLINT(modernize-use-override)
223  {
224  Nodelet::onInit();
226 
227  pnh_->param("queue_size", queue_size_, 3);
228  pnh_->param("debug_view", debug_view_, false);
229  if (debug_view_)
230  {
231  always_subscribe_ = true;
232  }
233  prev_stamp_ = ros::Time(0, 0);
234 
235  window_name_ = "Demo code to find contours in an image";
236  low_threshold_ = 100; // only for canny
237 
238  reconfigure_server_ = boost::make_shared<dynamic_reconfigure::Server<Config> >(*pnh_);
239  dynamic_reconfigure::Server<Config>::CallbackType f =
240  boost::bind(&FindContoursNodelet::reconfigureCallback, this, _1, _2);
241  reconfigure_server_->setCallback(f);
242 
243  img_pub_ = advertiseImage(*pnh_, "image", 1);
244  msg_pub_ = advertise<opencv_apps::ContourArrayStamped>(*pnh_, "contours", 1);
245 
247  }
248 };
250 } // namespace opencv_apps
251 
252 namespace find_contours
253 {
255 {
256 public:
257  virtual void onInit() // NOLINT(modernize-use-override)
258  {
259  ROS_WARN("DeprecationWarning: Nodelet find_contours/find_contours is deprecated, "
260  "and renamed to opencv_apps/find_contours.");
262  }
263 };
264 } // namespace find_contours
265 
CvImageConstPtr toCvShare(const sensor_msgs::ImageConstPtr &source, const std::string &encoding=std::string())
#define NODELET_ERROR(...)
void publish(const boost::shared_ptr< M > &message) const
image_transport::Publisher img_pub_
f
Nodelet to automatically subscribe/unsubscribe topics according to subscription of advertised topics...
Definition: nodelet.h:70
boost::shared_ptr< ReconfigureServer > reconfigure_server_
PLUGINLIB_EXPORT_CLASS(opencv_apps::FindContoursNodelet, nodelet::Nodelet)
Demo code to calculate moments.
Definition: nodelet.h:48
void subscribe()
This method is called when publisher is subscribed by other nodes. Set up subscribers in this method...
boost::shared_ptr< ros::NodeHandle > pnh_
Shared pointer to private nodehandle.
Definition: nodelet.h:250
#define ROS_WARN(...)
void doWork(const sensor_msgs::ImageConstPtr &msg, const std::string &input_frame_from_msg)
bool always_subscribe_
A flag to disable watching mechanism and always subscribe input topics. It can be specified via ~alwa...
Definition: nodelet.h:273
virtual void onInitPostProcess()
Post processing of initialization of nodelet. You need to call this method in order to use always_sub...
Definition: nodelet.cpp:57
virtual void onInit()
Initialize nodehandles nh_ and pnh_. Subclass should call this method in its onInit method...
Definition: nodelet.cpp:40
void publish(const sensor_msgs::Image &message) const
virtual void onInit()
Initialize nodehandles nh_ and pnh_. Subclass should call this method in its onInit method...
void imageCallback(const sensor_msgs::ImageConstPtr &msg)
boost::shared_ptr< image_transport::ImageTransport > it_
boost::shared_ptr< ros::NodeHandle > nh_
Shared pointer to nodehandle.
Definition: nodelet.h:245
image_transport::CameraSubscriber cam_sub_
opencv_apps::FindContoursConfig Config
image_transport::Publisher advertiseImage(ros::NodeHandle &nh, const std::string &topic, int queue_size)
Advertise an image topic and watch the publisher. Publishers which are created by this method...
Definition: nodelet.h:180
void unsubscribe()
This method is called when publisher is unsubscribed by other nodes. Shut down subscribers in this me...
image_transport::Subscriber img_sub_
const std::string & frameWithDefault(const std::string &frame, const std::string &image_frame)
void reconfigureCallback(Config &new_config, uint32_t level)
virtual void onInit()
Initialize nodehandles nh_ and pnh_. Subclass should call this method in its onInit method...
#define NODELET_DEBUG(...)
sensor_msgs::ImagePtr toImageMsg() const
void imageCallbackWithInfo(const sensor_msgs::ImageConstPtr &msg, const sensor_msgs::CameraInfoConstPtr &cam_info)
dynamic_reconfigure::Server< Config > ReconfigureServer
static void trackbarCallback(int, void *)


opencv_apps
Author(s): Kei Okada
autogenerated on Wed Apr 24 2019 03:00:17