fvviewer - Man Page

View FireVision images from various sources


fvviewer [options] -s shmem_id
fvviewer [options] -n host[:port]/image_id
fvviewer [options] -f file
fvviewer [options] camera argument string


Retrieve images via FireVision and display them in a X11 window.

In the first form the image is read from a shared memory image segment with the given shmem_id on the local host. The second form retrieves the image via the network and FireVision Fountain connecting to the given host (and optionally port) and reading the image for image_id. The third format allows for reading an image from the given file.

The last form is the most flexible as it allows you to pass in an arbitrary camera argument string to open any camera supported by FireVision.

All forms share common options described below. Additionally there are keys that can be pressed in the window to influence the behavior. By default the viewer will start with continuous mode disabled, that means that the user needs to press the space button to retrieve the next image.



Show usage instructions.


Start in continuous mode.

-s shmem_id

Open image from local shared memory segment with ID shmem_id.

-n host[:port]]/image_id

Open image via the network. The argument defines the host and optionally port to connect to, and the image_id to retrieve.


Retrieve images JPEG compressed (network retrieval only). This conserves bandwidth but also lowers the image quality.

-d delay

Delay in ms to wait before a new image is captured after the previous one has been received. This is especially useful for continuous local shared memory display.

-f file

Read image from 'file.

-o shmem_id

Write the incoming image into a local shared memory segment with the given ID. This can be used for quickly relaying images for debugging.


Verbose console output.



Toggle continuous mode.


Rectify image. Asks for a rectification info file and will show the rectified image. The rectification is performed locally.


Increase or decrease the delay by 5 ms respectively.


Rectify image, but use the already loaded rectification file and do not query again. Only useful after r has already been used, for example to quickly toggle between the rectified and non-rectified versions.


Refresh the image (in non-continuous mode).


Quit the viewer.


fvviewer -n myrobot/my_image

Read the image with the the ID my_image via the network from the host myrobot.

See Also

fawkes(8), fvnet(1), fvshmem(1)


Written by Tim Niemueller <niemueller@kbsg.rwth-aachen.de>


Documentation by Tim Niemueller <niemueller@kbsg.rwth-aachen.de>


Part of the Fawkes Robot Software Framework. Project website is at http://www.fawkesrobotics.org


11/25/2021 Fawkes 1.3.0 Fawkes Manual