Jump to content

The images acquired from Vision acquisition are not the same as the test preview when done with different Exposure values


Recommended Posts

Posted

I need to take three pictures with different exposure values. I used vision acquisition for this. I tried using the finite acquisition but I could not find a way to set a different exposure value for different pictures. I used the single acquisition 3 times in a flat sequence with 2 seconds of gap. When I take a test picture with vision acquisition it looks fine but when I run it in the program, they are not at all the same. Sometimes two pictures are the same, sometimes it is just white and sometimes the higher exposure value is brighter than the lower one.

Help please

post-37064-0-72249500-1373378303_thumb.p

Posted

Not sure about the exposure, but if you want 2 seconds delay between acquisitions, you'll need to change something. One way is to wire the Error Out of the first acquisition into a single-frame sequence that only has the Wait (ms). Then wire the error wire through that frame and into the second acquisition.

 

Does the Vision Assistant allow you to right-click and "convert to code", or so?

Posted

No it doesn't provide allow to change it to VI . I would like to take the pictures with as little delay as possible. I just put 2 seconds to try it. I tried what you said but it didn't work.

And everytime it is a random error:

I have attached the errors here
In Error1, the picture is just white. No image.

In Error2, the one with the lowest exposure has the brightest image.
Any ideas?

 

 

post-37064-0-81508200-1373470802_thumb.p

post-37064-0-34892400-1373470805_thumb.p

Posted
  On 7/10/2013 at 3:46 PM, intern said:
No it doesn't provide allow to change it to VI .

 

Yes, yes it does.  You are looking for "Open Front Panel" when you right click.  Works for the acquisition and assistant express VIs (and every express VI I've seen).

Posted

Oh ok. Thanks I didn't know that.
This is a snippet of one. Individually they work fine but again it's the same thing with same random errors.

 

post-37064-0-76238100-1373528092_thumb.p

Posted

Perhaps don't call Close Camera until all three snaps are taken. Wait, where are you setting the exposure? In MAX?

Posted

Turns out instead of delaying, I should have taken more pictures because the camera needed time to adjust to the new exposure.
Putting it in a while loop for a few iterations and using the last image solved this. 
Thanks for your help :)

Cheers

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Unfortunately, your content contains terms that we do not allow. Please edit your content to remove the highlighted words below.
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.