How to extract image from video with flat field

[HeNe5]

Hello 

I reach out to you because I'm just starting in LabView and I'm facing a problem. I am working with a basler ace camera which gives me a video and i'm perfectly ok with that. 

However, I need to build a luminance meter from this camera, which implies first using flat field before the luminance conversion. In a static point of view, there's no problem I can do it. 

But I'd like to have a continuous video in order to aim at my subject, and with a touch of a button, it would take a picture, and then make it through flat field correction tool to display it later. 

Thank you in advance

T. 

[rolfk]

You need to be a lot more specific about what your current setup does. You mention being new with LabViEW and using this Basler camera, all in the same alinea.

So does that mean that you have already a LabVIEW program written that interfaces to this camera and generates a video file?

Or do you have a standalone app that shows the camera image on screen and now want to go and write a LabVIEW program that does the same and then some?

That's a huge difference. In the first case you have a working LabVIEW program that needs to have some modifications applied to, in the second case you need to write a full LabVIEW application first, and with having stated that you are new to LabVIEW that is not something to be taken easily.

From what you describe I don't think it is impossible to do at all, but even for someone with almost 30 years of writing LabVIEW applications and even some vision experience, it's not something I would attempt to do in a few hours!

[HeNe5]

Hi Rolf, thank you for responding so quickly. 

What I mean being new to Labview is that I began working on this software 6 months ago. My experience is indeed quite poor compared to yours. 

Let me go from the beginning. I do have a Basler Ace camera that I can use with the Basler software, and it works very well. However, acquiring an image from the camera is only a small part in the whole work I was asked to deliver. 

In order to create my video luminancemeter, I first need to acquire a continuous video in the interface so that I can aim at the subject. I can do that, the example VIs given by Labview are perfect for that. 

From that video, I must extract a picture which will undergo a flat field correction. From that picture, I need to turn it into an array an extract pixel values. The conversion in luminance is then quite easy for me. 
However, my mind is lost regarding extracting a picture from the video and make it through a flat field correction. 

The interface should be for example a frame at the left with the video (in order to aim), and at its right, at the click of a button, a snap of the scene with a flat field correction. 

Be sure I’m making my best to make it understandable for you. Hope it works. 

Many thanks in advance. 

T.

[HeNe5 · Accepted solution]

Actually managed to extract the image from the video. I used the Buffer fonction and it worked perfectly. 

I can now apply vignetting treatment to my image. 

Thanks to you. 

T.