Remove the the background form the image

[Shaun07]

 

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.

 

Thanks,

Shaun

removebackground.vi

[smithd]

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:

Quote

 

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.

[Shaun07]

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?

 

Thanks