HSV and thresholding for marine growth project

I am doing marine growth detection project. In that i am using adaptive thresholding method to calculate threshold value for all image to detect marine growth. But thershold value could not detect the marine growth part on the image correctly..

before this, i have found the same question like me, but certain part that i didn't understand. this questions

"https://www.mathworks.com/matlabcentral/answers/167993-threshold-value-question-using-otsu-method?s_tid=srchtitle"

this is the image, actually the entire image has growth on it.

Can anyone please give some other method to find threshold value other than adaptive thresholding method that is suitable to separate the marine growth part and the background.

[Image Analyst]

You forgot to show us the regions that you consider to have growth on them. To me, it looks like everything in that image has at least some growth on it. Can you post images with no growth at all, a little growth, and heavy growth?

[Asmalina Mohamed Saat]

The region that I want to focus is all over the image

Actually I do this project based on timeline, according to timeline, its growth will increase all the time. plus this picture I took after I immerse the plate under the sea water .. the interval I took was a difference of 7 days, here is my picture based on the timeline

the arrangement of image are from 7, 15, 29, 34 days

Answer 1

[Image Analyst]

It looks like it's 100% covered after day 7. I would not recommend imaging. Once the blue background is covered, imaging can't determine how much is caked on, unless you want to do something like microCT on it. I would recommend you simply weigh the panel.