GV FAE Knowledge

Article ID: GV4-21-07-29
Release Date: 07/29/2021

Applied to
GV-FR Panel firmware V1.2.0 or later

Introduction
This guideline provides a quantified outline of GV-FR Panel’s face recognition capabilities to help users better understand the possible face recognition results, and in choosing the optimal minimum face size for GV-FR Panel.

A. Optimal Face Recognition Distance and Face Size Setting
Consider the following concepts when adjusting the minimum face size to achieve the desired face recognition result.

1. On the local settings page of GV-FR Panel, select the minimum face size in pixels, under the option Min. Face Size, which includes 80 x 80, 100 x 100, 120 x 120, 140 x 140, and 160 x 160.

   

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2. Lower minimum face size yields longer face recognition distance, higher minimum face size yields shorter face recognition distance.
3. Longer face recognition distance yields more face recognitions and more unwanted results, shorter face recognition distance yields less face recognitions and more precise results.
4. GV-FR Panel will only recognize and capture faces at a face size higher than the minimum face size set to trigger face recognition. For example, if the minimum face size is set to 140 x 140, GV-FR Panel will recognize and capture faces at face size 186 x 186, 173 x 173, 154 x 154, or 143 x 143.

Refer to the table below to select the most suitable minimum face size for your desired face recognition distance. Note: The “actual face size captured” values in the table are used simply as a reference and vary based on different face sizes detected in real environments, thus the “maximum face recognition distance” also varies accordingly.

For a visual understanding of the recognition result based on different face sizes, refer to the image samples below. B. Potential Issue and Recommended Face Size Setting
Potential Issue
Based on the table in A. Optimal Face Recognition Distance and Face Size Setting, setting the minimum face size to 80 x 80 on GV-FR Panel will enable the recognition of all faces from as far as 140 cm (4.59 ft) away. This may become a problem for controlled gates or doors where only the authorized personnel should pass through. In a situation where an unauthorized personnel is closer to the GV-FR Panel than an authorized personnel being recognized is, the controlled gate or door will still open for the authorized personnel. Whether orchestrated or by coincidence, the unauthorized personnel can immediately pass through this opening.

Recommended Face Size Setting
As a solution to the above-mentioned potential issue, it is recommended to set the minimum face size to 140 x 140 or 160 x 160 on GV-FR Panel. At this minimum face size, faces will be detected only if they are no more than 50 cm (1.64 ft) or 80 cm (2.62 ft) away from the GV-FR Panel, which will make far less face recognitions than the amount detected within 140 cm (4.59 ft). Using a large minimum face size value can greatly reduce the number of unwanted face recognitions and produce accurate recognition of authorized personnel at critical access points. Setting the minimum face size to 140 x 140 or 160 x 160 is an essential procedure for crowded locations, such as, corporations, event venues, or public transportations, to ensure accurate screening of those who are authorized to enter and those who are not.