Setting an adaptive threshold for image binarization

Hello everyone.

Does any of you have any idea on how to set an adaptive threshold on images similar to ones I have attached below in order to binarize the image so that the luminous LED become 1 and other pixels in the background become 0?

I have tried adaptive thresholding and Otsu thresholding techniques but non of them returned reliable results.

I do not expect to extactly extract all luminous LEDs from image but at least 80% of them must be found.

By the way, I also use watershed segmentation after binarizing the image, so if 2-3 LEDs are connected together after binarization, it's not a big deal :)

Any Method other than thesholding for finding the position of LEDs is also appreciated.