Society of Robots - Robot Forum

General Misc => Misc => Topic started by: Joker94 on May 20, 2010, 02:54:40 AM

Title: Blackfin in a UAV
Post by: Joker94 on May 20, 2010, 02:54:40 AM
What do you guys think?

The UAV will be at a constant hight of 200 to 400 feet and it needs to be able to spot a person near a car.

Since i have no experience of the black fins i wouldnt know if it would work ok. would it it?

i dont need a specific answer just for people opinion on the matter

cheers

Joker94
Title: Re: Blackfin in a UAV
Post by: Webbot on May 20, 2010, 06:40:33 AM
Bear in mind that cameras like the Blackfin generate a frame of pixels which is far too big to transmit to another processor. eg 320 x 200 pixels = 64,000 bytes
Equally 64k is a lot  of RAM.
Therefore all image processing is normally done on the camera.
The most common feature is to look for blobs eg any rectangles whose pixels are within a min/max colour range.
These blobs are then detected as the camera is transmitting the scan lines - ie the camera hardware doesn't need to store the whole image either.

So if the car is a red car and the person is wearing blue then you stand a chance of detecting and distinguishing them both. But if you need to detect any colour car and a person dressed in any colour then you've got a much bigger job as you are performing shape detection. You would probably need to write that code and then upload it to the Blackfin to replace its default image processing.
Title: Re: Blackfin in a UAV
Post by: Joker94 on May 21, 2010, 06:54:12 AM
thanks webbot

i think at this stage we are going with a surveillance style camera and a 10w video transmitter. an i am sure i will have a question or 2 over the next few months

Thanks for your help

Joker94
Title: Re: Blackfin in a UAV
Post by: Admin on May 31, 2010, 09:07:00 PM
What do you mean by "needs to be able to spot a person near a car."

You mean like autonomous face detection? Or just enough pixels that if you looked at the video feed you could tell it was a person in the car?
Title: Re: Blackfin in a UAV
Post by: Joker94 on June 01, 2010, 02:13:38 AM
It has to spot a person near a car from between 200 and 400 feet.

I have ruled out the blackfin though, going with a normal AV camera

i was looking at the blackfin as it had UART but i dont need it anymore.

Cheers

Joker94
Title: Re: Blackfin in a UAV
Post by: Admin on June 01, 2010, 03:18:44 AM
You didn't answer my question :P
Title: Re: Blackfin in a UAV
Post by: Joker94 on June 01, 2010, 03:44:47 AM
Sorry admin.

no nothing that detailed, we just have to be able to see the dummy laying there so we can initiate the bottle drop rig.

Cheers

Joker94
Title: Re: Blackfin in a UAV
Post by: Admin on June 01, 2010, 03:49:54 AM
The reason I asked is I wasn't sure if you wanted on-board computer vision, or just a camera for normal video.

For normal video, the Blackfin/CMUcam is definitely *NOT* a good choice :P