Average value of the white areas in the image

I have an image which has 13*11 bright spots(actually squares) I need to find the average value of the spots. I need 13*11 values from this single image. How can I do it?

[Matt J]

I do not see 13*11 spots. The upper rows have 13 spots, but the lower rows have more like 10.

[Adam]

It's not a clearly defined problem. For example, you could simply threshold the image to give a mask containing only those points with R, G and B values above 0.9 (or 0.8 or whatever threshold you choose) and then simply take the mean of all those points.

[Varun Meeniga]

I have marked some white blobs. I want the average value of the selected region. As such I want 11*13 values. Some blobs aren't there because the object covered them.

I also gave the image I took. Basically I'm doing dual photography (https://graphics.stanford.edu/papers/dual_photography/)