Analysing image to quantify liquid area

[Simon O]

I am analysing acquired images of vessels containing liquid. I wish to quantify the area of the image that is air or bubbles. I would like to trace a boundary around the bubble or bubbles but I am finding it difficult to perform this with IMAQ vision.

I have enclosed 3 test images and would like some help on how to do this. I have tried the verticl clamp and curve extraction but I cannot get an outline of the bubble.

Any help would be greatly appreciated.

Simon Orchard MSc

[Xu]

Hi Simon,

You can try to binarize the image, then use particle analysis VI(s) in NI Vision to get position, area, perimeter, etc.

[Simon O]

Thanks, but I have tried this and have not really had a lot of success getting a pixel area value, can you demonstrate??

Thanks

Simon

[AlexxxR]

Hi Simon,

attached you will find a Vision Assistant 8.2.1 Script, which gives you back the Areas of the bubbles!

Best regards

Alex Rudolph

NI Switzerland

[Simon O]

Alex

Thanks but the zip file contains only the images I have posted here already and an SCR screensaver file.

Please actually send the Labview code

regards

Simon

[Simon O]

Alex

I only use Vision Assistant 8.0.0. Can I have the script in this format

Many Thanks

Simon

[AlexxxR]

Hi,

*.scr is not a Screensaver, it´s the extension of a Vision Assistant Script File.

Attached you will find one for Version 8.0

Best regards

Alex

[Simon O]

Alex

Thanks however the script does not analyse the bubble. It analyses the white spots on the image. I have been able to this so far.Tthe bubbles are the items with a thick black border around them and I am having trouble detecting these as the border of the vessel is at the same contrast level.

regards

Simon

[Xu]

I also thought the white spots were bubbles.

If the posiiton of vessel in images is fixed, try this way:

* acquire an image of the vessel without any bubble as a background image,

* binarize all images including the background image

* do subtractions between binary images with bubbles and binary image of the background

* fill the particles

* some other morphorlogy operations may be needed before or after filling.

* particle analysys

Good luck,

[Simon O]

Thanks but I have tried all of this and cannot get a solution correctly. Thanks again but it looks as if i need to look for help elsewhere

regards

Simon