Flickerless

Flickerless Mode

The HVCS Hi-Res model has a maximum full frame rate of only 25fps. This produces a noticable flicker. To reduce the flicker, the flickerless mode can be used.

This will reduce the size of the image to only 640 pixel height which allows a frame rate of nearly 40 fps. The gain boost will be turned on so that the flash duration can be decreased to maintain the same LED exposure level.

The image will be shifted (panned) so that the visible flickerless window is aligned with the top left corner of the Live Video window.

When a recording is started, CapiMetrics will switch back to full frame, the user frame rate, turn the gain boost back to unity and adjust the flash duration. At the end of recording CapiMetrics will switch back to flickerless mode.

Flickerless mode can be switched on or off using menu Settings, Flickerless, or using the keyboard ~ key.

The first few frames of the recording may only show the flickerless window due to a delay in the driver applying the changes.

The following parameters can be changed in the ini file:

[ueye]
flessEN=0
flessh=640
flessfps=39.5
flessx=2.5

flessEN

enables flickerless mode

flessh

height of flickerless window in pixels

flessfps

frames per second for flickerless mode

flessx

factor to adjust the flash duration when switching betwwen flickerless and normal modes