Prophesee EVK4
Introduce EVK4, point to doc, setup example by changing bias etc… include use with kinect. recording datas. getting right format.
Introduction and setup
The Prophesee EVK4 is a dynamic vision sensor that delivers events when a change of brightness occurs. More precisely, ON and OFF events are generated when the brigthness rises or lowers respectively. It can generate events on a scale of nanoseconds and has a resolution of 1280x720. The installation and setup can be found on the Prophesee website
In our case, we will use a robotic setup where the camera is mounted on top of a table with a robotic arm in sight. The purpose is to observe objects moving and combine the events generated by the EVK4 with a Kinect depth camera to perform sensor fusion.
Tuning Bias
The most important parameters to consider in order to calibrate the camera to your environment are the bias. A well calibrated camera can make a tremondous difference in the quality of the datas generated. As examples, we recorded a ball rolling on the table and displayed the events at 100fps with an accumulation time of 20ms. This sample is a raw recording without any tuning.
In this one, we changed the bias settings.
Event Processing
The details of the following parameters can be found here
In case of noisy lightning with direct sunlight, the anti-flickering parameter can perform some filtering. In our setup, this parameter was not necessary however you can have an insight of what the events should look like.
The more useful parameter is the event trail settings. Depending on the light source conditions, a moving object always leaves a certain trail of events. We tuned here the trail filtering with a CUT option.
The KEEP trail option is also available>
ROI
Finally, it is often necessary to select a Region of Interest for a more efficient generation of events. It allows to remove unnecessary noise and focus on a specific location of the scene.
Same ROi but with the object moving horizontally to demonstrate the resized window of events.
