Web page

system: device provider: camera/web app ready introduced in v0.1 pull

Web page emulates camera to deliver a screenshot of a page. Since we can’t guarantee that the web source is in the same network where master server is, we have to use worker to proxy this process.

Web page requires headless Chrome running in the same network with a worker.

Configuration options

Param Required Type Default Description
address true string URL of a web page to take screenshots of. If protocol is not specified, http: will be used
chromeAddress true ipv4 Chrome IP address
chromePort int 9222 Chrome debug API port
pollingInterval int 30 Interval in seconds to wait between pulling updates from Chrome
reloadInterval int 0 Interval in minutes to wait before reloading original page: sometimes Chrome hangs on a gif images, this will help to prevent the issue
width int 800 Emulated page width
height int 600 Emulated page height

Note that width is “overriding” default camera’s setting and used instead for Chrome’s page width.

To configure emulator’s resolution, you can use Chrome developer tools. Select Responsive from the devices’ dropdown.

Supported properties

Property Type Description
picture string Base64-encoded string of JPEG image
distance int Hamming distance

Supported commands

Command Input Description
take-picture Forces to take a screenshot


system: device
provider: camera/web
address: https://www.ready.noaa.gov/data/forecast/grads/nam/panel10/anim.gif
pollingInterval: 15
reloadInterval: 10
width: 760
height: 587
quality: 50