How to calculate the area of the spark plasma

Dear community member,

In order to continue processing data for the experiment results, I have to calculate the spark plasma area based on the image.

The imageis in 511 x 415 pixels and the spark origin is located at (264,385) coordinate. Previously, I got a relatively similar code from Image Analyst to calculate the spray area as a reference. However, because the plasma area is brighter than surrounding area, its hard to capture the plasma area if the original image is converted into grayImage.

Please kindly guide me to resolve this problem.

The image that will be processed is also attached.

Thank you again for your kindness and support.

Answer 1

[Yash]

Hello Komang,

I understand you want to find the spark plasma area, but the plasma area is brighter which is causing issues in analysing the image. You want to distinct between plasma pixels with high intensity and the background with low intensity values.

Thresholding is useful in this case because it can separate the brighter spark plasma area from the darker surrounding area. By setting a threshold value, all pixels with intensities above the threshold are set to white, while all pixels with intensities below the threshold are set to black. This creates a binary image where the spark plasma area is white and the surrounding area is black, making it easier to calculate the area of the spark plasma.

To know about thresholding algorithms in MATLAB, you can refer to this page: https://in.mathworks.com/discovery/image-thresholding.html

I hope this helps!

[I Komang Gede Tryas Agameru Putra]

Dear Yash,

Thank you for providing insights. However, the spark plasma has a relatively small area, and there is some dirt in the image. Consequently, the dirt is being incorrectly identified as plasma. Please refer to the attached image.

What would be the most effective approach for distinguishing the dirt in this situation?

Thank you.