Dahua Emotion Recognition Analytics TestedBy Rob Kilpatrick, Published Dec 21, 2020, 11:02am EST (Research)
The advance of AI promises more sophisticated recognition. For example, Dahua markets the ability to distinguish between angry, calm, confused, disgusted, happy, sad, scared, and surprised.
We tested the Dahua IPC-HDBW7442H-IPZ running these analytics, examining:
- How accurate is emotion detection?
- Does accuracy vary depending on emotion?
- How does the angle of incident impact accuracy?
- How does distance/PPF impact accuracy?
- Does facial hair impact accuracy?
- Do face coverings affect detection?
Dahua's emotion detection made frequent mistakes, though its most common categorization was 'calm' for people who had neutral/expressionless faces, which is the most common state for people. Happy and confused were accurate most of the time, while angry, disgusted, sad, scared, and surprised worked poorly.
This chart provides an overview of the performance for each category Dahua offered:
Because the camera attempts to classify emotions any time a face is detected, even when blocked, facing away, or low PPF, along with its tendency to classify subjects as "Calm" in these instances, the analytic may appear accurate, since most subjects are likely to be expressionless most of the time.
Best Accuracy At High PPF/Shallow Angle (But Still Significant Issues)
In our testing, we began with a simple scene, well lit, at a low angle of incidence, with subjects facing the camera at close range to eliminate possible factors such as harsh angles or low PPF.
Even in these conditions, emotion detection was mostly inaccurate. The only expressions consistently accurately detected were Happy:
And Calm (although the camera classified users as Calm under many conditions, discussed below):
However, other expressions such as angry, sad, surprised, or scared were most often detected as calm, or sometimes happy.
Accuracy Worse At Harsher Angles and Lower PPF
At angles of incidence greater than ~45°, most subjects were classified as Calm, regardless of their actual facial expression.
The camera even classified the backs of subjects' heads as calm during testing:
Similarly, at low PPFs, subjects were only classified as Calm or Happy.
Incorrect Classification When Face Obscured
Since the camera attempts to classify emotions any time a face is detected, it attempted to classify even with much of the subject's face obscured. For example, when partially blocked by cardboard, the camera still classified the subject, but only as Calm and Happy.
Reduced Accuracy On People With Facial Hair
During testing, people with facial hair expressing a facial emotion were missed and instead mostly considered calm, below the person with a beard and angry face were not classified as angry.
No Sad Or Angry Classification
In our tests, no face was ever classified as sad or angry, instead, they were mostly classified as confused, happy, or calm. Below, the person has an angry face but is classified as calm.
Confused Accurate On People Without Facial Hair
People walking through the scene that were showing a clear confused face that was not obscured by facial hair were accurately detected.
Though when people were confused and had facial hair, Dahua emotion analytics did not accurately detect the emotion.
Disgusted Inconsistent Detection
The disgusted emotion was sometimes detected on a person walking through the scene with a clear disgusted expression.
However, most of the time the disgusted expression was not detected, even on an exaggerated attempt to get it to classify.
Emotion detection setup is simple, the user must turn on video metadata in settings, and then it will show the metadata including the emotion classification on the live view screen.
Tech Support And Dahua Feedback
Dahua USA tech support tried but was unable to help improve emotion detection, beyond getting a clearer shot of the face, while Dahua management did not reply to our request to comment on the performance.
The Dahua IPC-HDBW7442H-IPZ can be found online for ~$920 USD.
The following versions were used during testing.
- Dahua IPC-HDBW7442H-IPZ: V2.800.0000000.5.R, Build Date: 2020-05-25
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