Usage

Viewing a single image topic

rosrun image_view image_view image:=<image topic> [image transport type]

For example, to view raw images on the topic /camera/image, use:

rosrun image_view image_view image:=/camera/image

You may save the current image by right-clicking on the display window. By default, images will be saved as frame0000.jpg, frame0001.jpg, ....

If you want to view a compressed image stream (usually a good idea over wireless!) using the capabilities of image_transport, specify the transport type as a command-line argument. For example, if theora_image_transport is built on the publisher's side, you can use theora transport:

rosrun image_view image_view image:=/camera/image theora

Note that this is merely shorthand equivalent to setting the ~image_transport parameter:

rosrun image_view image_view image:=/camera/image _image_transport:=theora

Viewing stereo images

rosrun image_view stereo_view stereo:=<stereo namespace> image:=<image topic identifier>

For example, to view stereo image pairs on topics /my_stereo_cam/left/image_rect_color and /my_stereo_cam/right/image_rect_color, use:

rosrun image_view stereo_view stereo:=/my_stereo_cam image:=image_rect_color

stereo_view also shows the disparity image computed from the stereo pair, color-mapped for clarity.

You may save the current image pair by right-clicking on any display window. By default, images will be saved as left0000.jpg, right0000.jpg, disp0000.jpg, left0001.jpg, right0001.jpg, disp0001.jpg.... As with image_view, you can specify an image transport to use for the left and right image as an optional argument.

Nodes

image_view

Simple image viewer for ROS sensor_msgs/Image topics.

Subscribed Topics

image (sensor_msgs/Image)
  • The image topic. Should be remapped to the name of the real image topic.

Parameters

~autosize (bool, default: false)
  • Whether the window should autosize itself to the image or be resizeable by the user.
~filename_format (string, default: "frame%04i.jpg")
  • printf-style format for saved image names. Use to control name, location and format of saved images.
~image_transport (string, default: "raw")
  • Transport used for the image stream. image_view allows you to specify this as a simple command-line argument for convenience.
~window_name (string, default: name of the image topic)
  • The name of the display window.

disparity_view

Simple viewer for stereo_msgs/DisparityImage topics. Color-maps the disparity image for visualization.

Subscribed Topics

image (stereo_msgs/DisparityImage)
  • The disparity image topic. Should be remapped to the name of the real topic.

Parameters

~autosize (bool, default: false)
  • Whether the window should autosize itself to the image or be resizeable by the user.
~window_name (string, default: name of the image topic)
  • The name of the display window.

stereo_view

Viewer for stereo images. Shows the synchronized left/right image pair and the disparity image (color-mapped) computed from them.

Subscribed Topics

<stereo>/left/<image> (sensor_msgs/Image)
  • The left image topic. Formal parameters stereo and image should be remapped appropriately.
<stereo>/right/<image> (sensor_msgs/Image)
  • The right image topic. Formal parameters stereo and image should be remapped appropriately.
<stereo>/disparity (stereo_msgs/DisparityImage)
  • The disparity image computed from the left/right stereo pair.

Parameters

~autosize (bool, default: true)
  • Whether the windows should autosize to the image or be resizeable by the user.
~filename_format (string, default: "%s%04i.jpg")
  • printf-style format for saved image names. Use to control name, location and format of saved images. The string argument is "left" or "right".
~image_transport (string, default: "raw")
  • Transport used for the image streams.
~approximate_sync (bool, default: false)
  • Whether to use approximate synchronization. Set to true if the left and right cameras do not produce exactly synced timestamps.
~queue_size (int, default: 5)
  • Size of message queue for each synchronized topic. You may need to raise this if disparity processing takes too long, or if there are significant network delays.

Nodelets

image_view/image

Nodelet version of image_view. Brings up a display window for a sensor_msgs/Image topic.

Subscribed Topics

image (sensor_msgs/Image)
  • The image topic. Should be remapped to the name of the real image topic.

Parameters

~autosize (bool, default: false)
  • Whether the window should autosize itself to the image or be resizeable by the user.
~filename_format (string, default: "frame%04i.jpg")
  • printf-style format for saved image names. Use to control name, location and format of saved images.
~image_transport (string, default: "raw")
  • Transport used for the image stream. image_view allows you to specify this as a simple command-line argument for convenience.
~window_name (string, default: name of the image topic)
  • The name of the display window.

image_view/disparity

Nodelet version of disparity_view. Brings up a display window for a stereo_msgs/DisparityImage topic, color-mapped for visualization.

Subscribed Topics

image (stereo_msgs/DisparityImage)
  • The disparity image topic. Should be remapped to the name of the real topic.

Parameters

~autosize (bool, default: false)
  • Whether the window should autosize itself to the image or be resizeable by the user.
~window_name (string, default: name of the image topic)
  • The name of the display window.

Tools

image_saver

This tool allows you to save images as jpg/png file from streaming (ROS sensor_msgs/Image topic) to a file. From command line, you can run by rosrun image_view image_saver image:=[your topic], or see this answer to control the timing of capture.

Subscribed Topics

image (sensor_msgs/Image)
  • The image topic. Should be remapped to the name of the real image topic.

Services

save (std_srvs/Empty)
  • Save images, you need to set save_all_images to false

Parameters

~filename_format (string, default: left%04d.%s)
  • File name for saved images, you can use '%04i' for sequence number, and '%s' for default file format, you can use 'jpg' ,'png', 'pgm' as filename suffixes.
~encoding (string, default: 'bgr8')
  • Encoding type of input image topic.
~save_all_image (bool, default: true)
  • If you set false, images are only saved when 'save' service is called

extract_images

This tool also allows you to save images as jpg/png file from streaming (ROS sensor_msgs/Image topic) to a file. image_saver node provide very similar functionalities, such as providing service call to trigger the node to save images, save images other than Jpeg format, etc.

Subscribed Topics

image (sensor_msgs/Image)
  • The image topic. Should be remapped to the name of the real image topic.

Parameters

~filename_format (string, default: frame%04d.jpg)
  • File name for saved images, you must add use '%04i' for sequence number.
~sec_per_frame (double, default: '0.1')
  • set sec per frame value.

video_recorder

This tool allows you to record a video stream (ROS sensor_msgs/Image topic) to a file. It relies on OpenCV's VideoWriter class. With the default options, it encodes the video as MPG, encapsulated in a AVI container at 15 fps, and produces a file called output.avi in the current directory.

Subscribed Topics

image (sensor_msgs/Image)
  • The image topic. Should be remapped to the name of the real image topic.

Parameters

~filename (string, default: output.avi)
  • Path and name of the output video.
~fps (int, default: 15)
  • Framerate of the video.
~codec (string, default: MJPG)
  • The FOURCC identifier of the codec.
~encoding (string, default: bgr8)
  • The image color space of the video.

Wiki: image_view/diamondback (last edited 2016-05-26 20:22:17 by IsaacSaito)