Jump to content

Remove the the background form the image

Recommended Posts


Hello All,


I am new to the camera labview programming. 


For my research work, I am using camera to grab the live image. I am stuck with one problem. 

how to treat the background?

I tried to subtract the constant value from the entire image, but with that i am loosing few of my data.

I know one solution, but I don't know how to implement this solution. 

Problem: how to take the values from the 4 corner of the image and subtract those value from entire image?


If anybody previously develop similar stuff then please help me out for this. 


Any help would be appreciate.






Link to comment

If you really want the pixel values, you can get those (http://zone.ni.com/reference/en-XX/help/370281AC-01/imaqvision/imaq_getpixelvalue/) and then use the imaq subtract with a constant.

However: one thing you'll note is that many of the analysis functions have a "mask" input. One route to get rid of the background would be to use a threshold function to get a mask (https://forums.ni.com/t5/Example-Programs/IMAQ-Threshold-Binary-Image-and-Mask/ta-p/3534077) and then feed that mask into, as an example, the histogram function (http://zone.ni.com/reference/en-XX/help/370281AD-01/imaqvision/imaq_histogram/). Per the help:



Image Mask is an 8-bit image specifying the region in the image to use for the calculation. Only those pixels in the original image that correspond to an equivalent non-zero pixel in the mask image are used for the calculation. The entire image is used in the calculation if Image Mask is not connected.



On a related topic, it could be worth looking at http://www.ni.com/pdf/manuals/371007b.pdf and http://www.ni.com/pdf/manuals/322916b.pdf. I think both are now part of the imaq help (the second pdf became this, I believe: http://zone.ni.com/reference/en-XX/help/370281AD-01/TOC1.htm) but I find the PDF to be nicer to look at. So for example you might use the particle analysis functions or the edge detection functions to find your glowy dot and get other characteristics about it, depending on what you are looking to do.

Link to comment

Hello Smithd,


Thank you so much for suggestions. Definitely, all those suggestion gonna help me to figure out the pixel value. 

But, Did you implement any kind of background correction algorithm? related to what I am trying to do. (i.e. Averaging 4 corner values). 

Even though if you didn't do it do you have nay idea how to get the average values for all those corner?



Link to comment

Join the conversation

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

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.