I've had my little LPR test setup for a while, I've been happy with it (OpenALPR).
I noticed Sighthound has finally released their product (it still needs work IMO).
But I quickly noticed something.... You don't know what you don't know!
Sighthound reports vehicles & plates differently, they are not associated (that sorta sucks). But I noticed that it was detecting a lot more vehicles than itself or ALPR was reporting for plate detection.
So essentially, I did not know I was missing traffic. Here are some photos and what has been happening.
Here is a truck today at about noon.
My system starts missing vehicles in the afternoon, when the sun is lower in the sky. Essentially the plates are over exposed because the sun starts hitting them. Here is an example at 3:30 in the afternoon, still captured but you can see it is starting to over expose. Depending on how the sun hits the plates, I will get nothing.
I went into the camera and reduced the brightness. I had it set at 60 and dropped it all the way down to 10. This next photo is taken at 4:30, the plate looks great and the vehicle looks OK as well. However, if I had not dropped the brightness down to 10 I doubt the system would have captured that plate as the sun would have just blown it out.
I am thinking of using the camera's API to reduce the brightness levels when the sun is starting to go down and blowing out the plates. Just reducing the exposure based on time of day may not be too smart, what about if there is no sun or it is raining. Then I would be underexposing the video because I'm making adjustemets for expected sun but there is no sun on rain days.
Does anyone have any suggestions how they handle this situation? Everyone must be in the same situation, with too much light at one point of the day and different levels of exposure being required.
I noticed Sighthound has finally released their product (it still needs work IMO).
But I quickly noticed something.... You don't know what you don't know!
Sighthound reports vehicles & plates differently, they are not associated (that sorta sucks). But I noticed that it was detecting a lot more vehicles than itself or ALPR was reporting for plate detection.
So essentially, I did not know I was missing traffic. Here are some photos and what has been happening.
Here is a truck today at about noon.
My system starts missing vehicles in the afternoon, when the sun is lower in the sky. Essentially the plates are over exposed because the sun starts hitting them. Here is an example at 3:30 in the afternoon, still captured but you can see it is starting to over expose. Depending on how the sun hits the plates, I will get nothing.
I went into the camera and reduced the brightness. I had it set at 60 and dropped it all the way down to 10. This next photo is taken at 4:30, the plate looks great and the vehicle looks OK as well. However, if I had not dropped the brightness down to 10 I doubt the system would have captured that plate as the sun would have just blown it out.
I am thinking of using the camera's API to reduce the brightness levels when the sun is starting to go down and blowing out the plates. Just reducing the exposure based on time of day may not be too smart, what about if there is no sun or it is raining. Then I would be underexposing the video because I'm making adjustemets for expected sun but there is no sun on rain days.
Does anyone have any suggestions how they handle this situation? Everyone must be in the same situation, with too much light at one point of the day and different levels of exposure being required.
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