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frequency_cam

  • Software
  • Perception
  • Tool

A ROS/ROS2 node that colors each pixel of an event camera image by the frequency at which its brightness changes, producing a frequency image for periodic signals.

Made by ROS event camera support.

Source on GitHub: github.com/ros-event-camera/frequency_cam (opens in a new tab). Facts read at commit 7407326 (opens in a new tab).

Licenses

Code
Apache-2.0 (opens in a new tab)

Read by Robotheca from LICENSE (opens in a new tab) (Apache-2.0) at commit 7407326 (opens in a new tab), on 16 Oct 2026.

Commercial use
Yes

What it does

  • Colors pixels by the frequency of their brightness changes, yielding a frequency image similar to Prophesee's Metavision vibration module.
  • Uses an IIR digital filter to approximately reconstruct each pixel's brightness, then measures time between zero-level crossings.
  • Expects event_camera_msgs messages, typically from the metavision ROS driver; other cameras can be supported via conversion tools or the libcaer driver.
  • Parameters control the frequency range, filter cutoff, timeouts, publishing rate, log-scale coloring, overlay of event pixels, and legend appearance.
  • Can play from a bag file under ROS2 and write generated frames to disk, with optional image scaling.
  • Publishes the frequency image on a topic and subscribes to an event topic.

Written by Robotheca from the project's README (opens in a new tab) at commit 7407326.

Getting started

Difficulty
Advanced
Hardware it needs, as the project states it
Tested on Ubuntu 20.04 under ROS2 Galactic.

Maintenance

Status
Maintained: a commit in the last 12 months
Newest commit
26 Apr 2026 on master
Latest release
None published on GitHub

Checked on GitHub on 16 Oct 2026.

Links

Robots that can run it

No robot on Robotheca is linked to it yet. Links come from a robot's robot.yaml, from its dependency files read as text, or from Robotheca's editors.

Robotheca lists software as a reference: nothing is hosted or run here, and every fact links to where it was read.