Increase the frequency at which images are updated in a subscriber
I am using code which tracks the image of a robot. Specifically, [the rospy-based code I am using is...
View ArticleCreate a subscriber to an Image topic
Hi, Im trying to wrtie a node that subscribes to a image topic, however, after almost copying the ros tutorial, I keep getting an error. The relevant parts of my code are: ros::NodeHandle nh;...
View ArticleHow do I convert an ROS image into a numpy array?
Hi All, I'm trying to read ROS images published from a video camera (from MORSE) into a numpy array in my python script, but I don't know what is the correct way to do this, and everything I have tried...
View ArticleMATLAB 16uc1 or 32fc1 Conversion
I have some image processing code in MATLAB and am attempting to use it with ROS. I read in a PointCloud2 object and execute `readRGB(ptcloud)` and `readXYZ(ptcloud)` where I get two MATLAB images each...
View Articlesensor_msgs.msg Image type value error. "Not a message data class"
I'm getting a value error when trying to run this code: front_image_pub = rospy.Publisher('/front_camera/image_raw', Image, queue_size=10) The precise error is: Traceback (most recent call last): File...
View Articlecustom stereo camera publisher fails mysteriously
I'm trying to make a stereo camera for visual odometry. My Python script to publish the images consistently stops after ~500 images, with no errors. I have cameras plugged into the 2 CSI ports on the...
View ArticleConvert filtered PointCloud2 to Image
Hi everyone, I'm looking for a way to convert a filtered PointCloud2 from an RGBD camera (i.e. background removed, limited range etc.) back to an image as it might have be seen by the camera. The...
View Articledifferent encodings of depth image for real & simulated kinect
Hi all I've got a Gazebo simulation of a kinect camera, where I'm subscribing to the ROS topic `/camera/depth/image_raw`, which is of type...
View ArticleFinding pose in base coordinate when given input point on camera image
Hello, I'm a beginner to ROS, and I'm using ROS Indigo in Ubuntu 14.04. With mobile manipulator, I'm going to implement a teleoperation system which user can operate from a distance. Especially in...
View ArticleCan I use image transport for the two different image topics?
Using an RGBD camera (RealSense D435), we want to log compressed color images (JPEG 'compressed'), and depth images (PNG 'compressedDepth'). The realsense driver publishes these compressed topics...
View ArticleUSB camera does not take any pictures when ROS is launched at system startup
I have been trying to take pictures using a USB cam connected to my Jetson TX2. My code works pretty well when I execute it from terminal using the command `roslaunch my_ros my_launch_file.launch` and...
View ArticleRGB and Depth sensor_msgs::Image vs XYZRGB sensor_msgs::PointCloud2
Hello, So I have ROS running across multiple machines on a limited network, and I have two possibilities, transfer a XYZRGB sensor_msgs::PointCloud2 directly or two sensor_msgs::Image (one rgb and one...
View Articlerepublish image from rospy node to roscpp node
Hi, I just want to know the right format to republish image data from a python node to a cpp node, because I keep getting an error. My python node is publishing a CompressedImage (from sensor_msgs.msg...
View ArticleCreating a bag file out of a image sequence
Let's say I have a series of images and want to create a bag file out of them to use as input for the camera calibration. Is it even necessary to create the bag for the calibration or is there another...
View ArticleHow to take image from kinect and visualize using opencv?
I have a kinect set up using openni. I want to use opencv for further processing. When I use imgmsg_to_cv2() and cv2.imshow no image shows up and the terminal freezes. What am I missing? class Frame:...
View ArticlePointcloud transform issue
I have a setup where I am fusing PointCloud2 and cameras to get XYZIRGB cloud. pcl::PointCloud points_front, points_back; Both `points_back` and `points_front` come from a different lidar-camera pair....
View ArticleImage overlay with transparency (sensors_msg/Image) on mapviz
Hi everyone, I've written a simple node which reads in a png file with transparency and publishes it to a certain topic. The topic is then subscribed by mapviz to display the image as an overlay. While...
View ArticlePython: message_filter AttributeError when registering callback
So I've wrapped my python node in a class, and I've been trying to approximate sync two messages at once (one being `Image` and another custom message `ofMsg` that consists of two `Float32`s) as below:...
View ArticleWhy is ros image timestamp value so small?(Python)
Hello there, I'm trying to compute the delay of my program by printing the difference between time.time() and img.header.secs. As stated in the documentation both python's time and ros's timestamp are...
View ArticleSubscribing from 2 cameras simultaneously in sawyer robot
Hello, I was recently trying to follow along the code for displaying two camera images (from head and back end of the hand) from the sawyer one-handed robot. Here:...
View Articleros2 megapixel image pub/sub cpu usage is very high
When I try to publish and subscribe to rgb8 Images of around 1000x1000 at 20 Hz (or even 1 Hz) the cpu usage seems very high. (TODO make an apples-apples comparison with ros1, lower resolution images-...
View Articlecamera calibration algorithm
Hello everyone ! I've read all official tutorials of ros ( about topics and nodes, packages etc) then I wanted to calibrate my camera ( Bus 001 Device 002: ID 058f:3881 Alcor Micro Corp.)...
View ArticleHow to subcribe both Image topic and Text topic in the same time ?
Hi buddy, I am newbie in ROS. And this is the first time i'm trying to subcribe 2 topics type, 1 for Image topic and 1 for Array of ints topic. And i have a problem on it. This is my source code:...
View Articlecreate point cloud2 from depth image
Hi, I have a image message of depth image. I need to create point cloud2 from that message, how can I do it? I don't have camera info!!!. I couldn't find any document for that. please help me.
View ArticleDifference between image_transport::Subscriber AND ros::Subscriber?
What is the Difference between image_transport::Subscriber AND ros::Subscriber?. Which is more efficient?
View Articleno image received from rpicamera
i want to access the camera and display the image in rviz, however the camera node produces a grid visual with no error message associated. when i open the image node, it gives a warning...
View Articlesensor_msgs/Image data to sensor_msgs/CompressedImage data
I have an industrial camera (DVP interface), and I added some code in the driver to convert the cv image into ros image data. I want to use this camera to test the [fiducials...
View ArticleFailed to open big image file, map_file and map_server
I am using Kinetic and Ubuntu 16.04.6 LTS, I am trying to upload a map file for map_server and use it for navigation and amcl localization, but it is really big, 25500 x 5300 pixels (.pgm). The...
View ArticleSubscriber - perform callback on 'most current' data received
Hey everybody, I've been messing a bit with a subscriber node and i'm getting stuck. Little bit of background: I have a topic where a camera publishes images with a frequency of 10 hz (ish). I have...
View ArticleHow to create organized pointcloud from unorganized pointcloud?
I want to use [convert_pointcloud_to_image.cpp](https://github.com/ros-perception/perception_pcl/blob/kinetic-devel/pcl_ros/tools/convert_pointcloud_to_image.cpp) to convert an unorganized point cloud...
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