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Author Topic: Reducing noise from wireless camera  (Read 2648 times)

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Offline toastmanTopic starter

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Reducing noise from wireless camera
« on: February 27, 2007, 05:41:04 AM »
Hi... I've bought a wireless camera for my robot project, pic shown here:
http://img15.imgspot.com/?u=/u/07/57/07/Camera1172578791.jpg
But the image result is really noisy, sample result shown here:
http://img15.imgspot.com/?u=/u/07/57/07/Cap071172578992.jpg

Does anyone has any idea on how to reduce these noises? Either electronics wise or maybe using image processing algorithm... I need to detect the edges of the objects in the pic n i'm planning to do it using MATLAB. Thanks in advance...

Offline Admin

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Re: Reducing noise from wireless camera
« Reply #1 on: February 27, 2007, 05:57:19 AM »
several thoughts to try out:
check your battery
check connections if they are loose
what range are you operating at?

it is quite possible you have a defective camera . . .

Offline robot321

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Re: Reducing noise from wireless camera
« Reply #2 on: February 27, 2007, 07:33:32 AM »
ugg.. nasty.  I am also using a similar product for my project.

To help the picture without software.

1) add some more IR leds
2) check antenna connection/ fine tune the control knob
3) find new antenna.  I'm currently using an spare ATSC antenna  it really improved range and quality.

While I am using my own computer vision program (to save some cpu cycles)
You can also do these with roborealm.

1) ADD (current frame 1 and current frame 1)
2) Average 3 (The average of 3 frames)

These steps have drastically improved my quality to crystal clear.

NOTE:  The average 3 step might create a tad of lag depending on the speed of the processor and how many times you are grabbing the analogue frame.
« Last Edit: February 27, 2007, 07:43:06 AM by robot321 »

Offline hgordon

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Re: Reducing noise from wireless camera
« Reply #3 on: February 27, 2007, 08:52:00 AM »
Looks like it might be interference from another RF device.  Usually, those cameras have 4 channels, so try switching the channel to see if it makes any difference.

By the way, you'll also find that power consumption with that type of camera is quite high.  You might have better results using a small WiFi camera that sends the images digitally.
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Offline robot321

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Re: Reducing noise from wireless camera
« Reply #4 on: February 27, 2007, 01:41:21 PM »
My version uses 50mA.  Not that crazy in terms of power consumption.

It appears his version is 100mA. See example:
http://cgi.ebay.com/USB2-0-Wireless-CCTV-Camera-USB-Receiver-Free-DC-803U_W0QQitemZ220086840821QQihZ012QQcategoryZ48632QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

With my testing with the setup I have, the camera broadcast frequency will change based on the discharge curve of the power source.

Also consider a remote on/off switch for the camera and a new power source other than a 9v battery.
« Last Edit: February 27, 2007, 01:48:36 PM by robot321 »

Offline hgordon

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Re: Reducing noise from wireless camera
« Reply #5 on: February 27, 2007, 03:04:57 PM »
I hope you're right.  In my experience, analog wireless cameras will kill a 9V battery in less than 1 hour, but maybe there's a new generation of low power devices.  You might try to measure the current draw if you have a chance.
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Offline toastmanTopic starter

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Re: Reducing noise from wireless camera
« Reply #6 on: February 27, 2007, 07:51:39 PM »
Thanks for so many replies...  ;D

Quote
several thoughts to try out:
check your battery
check connections if they are loose
what range are you operating at?

it is quite possible you have a defective camera . . .

I'm using the given adaptor for first testing but later I will use battery. The picture above is taken with the use of the adapter. Connection seems to be pretty okay. The range is 1.2 GHz. I'm also afraid that it's defective but I hope it's not...  :-\

Quote
To help the picture without software.

1) add some more IR leds
2) check antenna connection/ fine tune the control knob

What do u mean by adding some more IR leds? Where to add? The antenna connection looks fine but there's only one freq tuner n it seems to be quite loose... no fine tune...

Quote
While I am using my own computer vision program (to save some cpu cycles)
You can also do these with roborealm.

1) ADD (current frame 1 and current frame 1)
2) Average 3 (The average of 3 frames)

This should be able to be done with matlab too, right? I think I'll try these two first... Thanks for the advice...

 


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