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Frame rate drop

Jul 31, 2012 at 3:55 PM

Hi All,

I am using GoblinXNA 4.1 for my app. If I change the resolution to Resolution._1280x720 when InitVideoCapture(), then the frame rate will drop to 12 - 20 FPS.

captureDevices.InitVideoCapture(0,FrameRate._60Hz, Resolution._1280x720, ImageFormat.R8G8B8_24, false

); 

 

The reason I decide to do this is because I am using Sony HUD that have display resolution of 1280x720.

Anyone know how to improve this? Thank

Truyen

 

 

Coordinator
Jul 31, 2012 at 8:40 PM

Any webcam app with 1280x720 resolution will be significantly slower than 640x480 resolution. Especially if you're doing marker tracking. More resolution means more computation on vision analysis.

Ohan

Jul 31, 2012 at 8:47 PM

Yeah, it is very slow. Well, just very excitting with Sony HUD http://www.amazon.com/Sony-HMZ-T1-Wearable-HDTV-2D/dp/B005SCYZGA

But seems that no way to improve this?

Thanks ohan

Coordinator
Aug 1, 2012 at 2:06 AM

Nope, nothing we can do about the camera capture speed. 

Coordinator
Aug 1, 2012 at 10:10 AM

By the way, I don't remember if State.ThreadOption is set to be ThreadOption.MarkerTracker. If not, you can try to multi-thread the capture process by setting this option in your initialization code.

Ohan

Aug 1, 2012 at 4:24 PM

Yes it is Ohan. I see this in the Initialize()

State

.ThreadOption = (ushort)ThreadOptions.MarkerTracking;

truyenle

Aug 1, 2012 at 10:52 PM

Continue testing it and I found that it is not only the resolution cause the frame rate drop. But opening the second real camera does drop a lot. I only got < 10 FPS?

We need to improve this else, the app won't work.

Any idea to improve please help.

Truyen

Coordinator
Aug 2, 2012 at 10:32 AM

We're doing stereoscopic AR with Vuzix Wrap920AR with 640x480 resolution all the time, and we get above 30 FPS performance. It's more likely that you're doing tracking on 1280x720 resolution. You may want to use HalfResizer, which will significantly improve the tracking speed (but may cause less stable tracking due to lower resolution). See how to use a resizer in Windows Phone version of Tutorial 8 (I didn't include an example for the PC version)

Ohan

Aug 2, 2012 at 8:30 PM

Yeah, you're right change the resolution higher than 640x480 cause the frame rate drop below 10.