Blank Frames

TDV
Posts: 11
Joined: Sat Feb 07, 2009 11:47 am

Blank Frames

Post by TDV »

Hello! May be someone know why where are blank frames at the start of shooting (5-6 frames from each camera) in "PC" and "Camera" modes? In greyscale mode I have data at the first frame. I tried to start cameras too earlier than I call GetObjectData or GetFrameImage first time, but the result is same.
Birch
Posts: 1139
Joined: Thu Jan 30, 2003 5:00 am
Location: Corvallis, Oregon

Re: Blank Frames

Post by Birch »

A couple questions :

Does this happen every time you "start" the cameras?

Which camera model (V100? C120?) are you using?

Are all the cameras in a sync-chain together?

How many cameras are you using?


You might also consider using SetVideo() in your application.

Here is a simplified example

Start();

SetVideo(false); // "pause" the camera

// use a loop here to
// drain down all the frames from the cameras to clear them out

SetVideo(true); // "un-pause" the camera
TDV
Posts: 11
Joined: Sat Feb 07, 2009 11:47 am

Re: Blank Frames

Post by TDV »

[quote=NaturalPoint - Birch Zimmer]
Does this happen every time you "start" the cameras?[/quote]
This is happening every time I "start" the cameras in "PC" or "Camera" modes.

[quote=NaturalPoint - Birch Zimmer]
Which camera model (V100? C120?) are you using?[/quote]
I'm using V100 cameras.

[quote=NaturalPoint - Birch Zimmer]
Are all the cameras in a sync-chain together?[/quote]
Yes.

[quote=NaturalPoint - Birch Zimmer]
How many cameras are you using?[/quote]
From 2 to 8 - the result is same.

[quote=NaturalPoint - Birch Zimmer]
You might also consider using SetVideo() in your application.[/quote]

Ok, I'll try do so, but in this case I probably will not have 100 fps, isn't it?
Birch
Posts: 1139
Joined: Thu Jan 30, 2003 5:00 am
Location: Corvallis, Oregon

Re: Blank Frames

Post by Birch »

[quote=TDV]
[quote=NaturalPoint - Birch Zimmer]
You might also consider using SetVideo() in your application.[/quote]

Ok, I'll try do so, but in this case I probably will not have 100 fps, isn't it?
[/quote]

Using SetVideo() to pause/un-pause should not interfere with the frame rate. As long as the cameras not in greyscale, getting 100FPS should be possible (100FPS greyscale with multiple cameras can be tricky).

Just call Start() once during your application init, and Stop() once before your app shuts down. Then use SetVideo() in place of where you would normally use Start() and Stop(). Once you've started the cameras running with SetVideo(true), you can leave them running as needed. When you need to stop them, call SetVideo(false).
TDV
Posts: 11
Joined: Sat Feb 07, 2009 11:47 am

Re: Blank Frames

Post by TDV »

Thank you for reply!

[quote=NaturalPoint - Birch Zimmer]
100FPS greyscale with multiple cameras can be tricky[/quote]

I already understood that )))

[quote=NaturalPoint - Birch Zimmer]
Just call Start() once during your application init, and Stop() once before your app shuts down. Then use SetVideo() in place of where you would normally use Start() and Stop(). Once you've started the cameras running with SetVideo(true), you can leave them running as needed. When you need to stop them, call SetVideo(false)[/quote]

Ok, I will try to do so and write here about results.
TDV
Posts: 11
Joined: Sat Feb 07, 2009 11:47 am

Re: Blank Frames

Post by TDV »

The SetVideo method didn't help me. Results are the same as earlier (two cameras in the sync chain):

camera 1:

Frame NO/ID: 0/34
Frame NO/ID: 1/35
Frame NO/ID: 2/36
Frame NO/ID: 3/37
Frame NO/ID: 4/38
Frame NO/ID: 5/3
Frame NO/ID: 6/48
Obj0 X = 302.4 Y = 200.6 W = 15 H = 14 A = 166
Frame NO/ID: 7/49
Obj0 X = 302.4 Y = 200.6 W = 15 H = 14 A = 166
Frame NO/ID: 8/50
Obj0 X = 302.3 Y = 200.6 W = 15 H = 14 A = 164
...

camera 2:

Frame NO/ID: 0/33
Frame NO/ID: 1/34
Frame NO/ID: 2/35
Frame NO/ID: 3/36
Frame NO/ID: 4/37
Frame NO/ID: 5/47
Frame NO/ID: 6/48
Obj0 X = 461.1 Y = 130.7 W = 15 H = 15 A = 175
Frame NO/ID: 7/49
Obj0 X = 461.1 Y = 130.7 W = 15 H = 15 A = 175
Frame NO/ID: 8/50
Obj0 X = 461.1 Y = 130.7 W = 16 H = 15 A = 176
...
Birch
Posts: 1139
Joined: Thu Jan 30, 2003 5:00 am
Location: Corvallis, Oregon

Re: Blank Frames

Post by Birch »

Can you send your code to support@naturalpoint.com for us to take a look?
TDV
Posts: 11
Joined: Sat Feb 07, 2009 11:47 am

Re: Blank Frames

Post by TDV »

Do you recieve my e-mail? I sent it two days ago.
VincentG
Posts: 7728
Joined: Mon Jul 17, 2006 5:00 am
Location: Corvallis, Oregon

Re: Blank Frames

Post by VincentG »

Email has been received
TDV
Posts: 11
Joined: Sat Feb 07, 2009 11:47 am

Re: Blank Frames

Post by TDV »

Hello! Can you say anything about my code?
Post Reply