This article describes how to address issues with ability to grant access in backlight conditions.
First evaluate what is preventing access granted action. Open SAFR SCAN Web Console Live view and run following tests:
- Is face being detected or does it take a long time to detect face (i.e. does it begin to put a box around the face)
- If not, then set Scene Exposure Region as described below.
- Is face matched and is this occurring within desired time)
- If not, face image may be old or not representative of current face. Try adding additional face as described in Adding Alternate Faces for Improved Face Matching
- Is face verified as live in timely manor (i.e. do you see green heart icon)
- If you see orange heart or no heart icon, then try adjusting Backlight compensation setting as described below.
- Alternatively, try adjusting Anti-spoofing level in the Access mode settings page.
- IF all else fails, try suggestions described in Other Settings below.
See SAFR SCAN Administrator Guide at http://docs.real.com guidance for more information on these settings.
Setting Scene Exposure Region
Go to Camera settings (See below)
Set Scene exposure to somewhere in view that results in initial exposure such that face is well lit. This should be a surface with a lot of reflection that does not get direct sun light. Often bushes or trees work well even if they are exposed to direct sun light. Doing this will allow safr scan to find a face quickly. If you find events are not appearing easily, this is the setting to focus on.
Adjust Backlight Compensation
Adjust Backlight compensation until you find performance is best. Start at Auto and move up to Slight backlight and further until a setting works well. Each option include the suggested conditions under which it works best.
Even when not set to Auto, SCAN will still perform well when the strong backlight is gone (i.e. evening) because it only invokes the behavior when a strong backlight condition exists.
Other Settings
If all else fails, try adjusting following
Shutter speed max - Reduce Shutter speed max to something like 1/120 (this ensures SCAN collects sufficient light on the face)
Exposure level - Resists adjustments to Exposure adjust speed - this is an advanced setting.