<<TOC(3)>>

== 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 left-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 left-clicking on either display window. By default, images will be saved as `left0000.jpg`, `right0000.jpg`, `left0001.jpg`, `right0001.jpg`....

== Nodes ==
{{{
#!clearsilver CS/NodeAPI
name = image_view
desc = Simple image viewer for ROS topics.
sub {
  0.name = image
  0.type = sensor_msgs/Image
  0.desc = The image topic. Should be remapped to the name of the real image topic.
}
param {
  0.name = ~autosize
  0.type = bool
  0.desc = Whether the window should autosize itself to the image or be resizeable by the user.
  0.default = false
  1.name = ~filename_format
  1.type = string
  1.desc = printf-style format for saved image names. Use to control name, location and format of saved images.
  1.default = `"frame%04i.jpg"`
  2.name = ~image_transport
  2.type = string
  2.desc = Transport used for the image stream. `image_view` allows you to specify this as a simple command-line argument for convenience.
  2.default = `"raw"`
  3.name = ~window_name
  3.type = string
  3.desc = The name of the display window.
  3.default = name of the image topic
}
}}}
{{{
#!clearsilver CS/NodeAPI
name = stereo_view
desc = Viewer for stereo images. Shows the left/right image pair and the disparity image (color-mapped) computed from them.
sub {
  0.name = <stereo>/left/<image>
  0.type = sensor_msgs/Image
  0.desc = The left image topic. Formal parameters `stereo` and `image` should be remapped appropriately.
  1.name = <stereo>/right/<image>
  1.type = sensor_msgs/Image
  1.desc = The right image topic. Formal parameters `stereo` and `image` should be remapped appropriately.
  2.name = <stereo>/disparity
  2.type = stereo_msgs/DisparityImage
  2.desc = The disparity image computed from the left/right stereo pair.
}
param {
  0.name = ~autosize
  0.type = bool
  0.desc = Whether the windows should autosize to the image or be resizeable by the user.
  0.default = true
  1.name = ~filename_format
  1.type = string
  1.desc = printf-style format for saved image names. Use to control name, location and format of saved images. The string argument is `"left"` or `"right"`.
  1.default = `"%s%04i.jpg"`
  2.name = ~image_transport
  2.type = string
  2.desc = Transport used for the image streams.
  2.default = `"raw"`
}
}}}