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Usage

Viewing a single image topic

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

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

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:

image_view image:=/camera/image theora

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

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

Viewing stereo images

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:

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.