How to count frequency of particles with particular area and store them as data?

This is the negative image of a soil sample, I need to set a lower limit for the area for example 0.01 square units. Above that value, I need to get the frequency of samples under a given range in the image present. For example Amin=0.01 square units Range: 0.1 square units Amax: 4 square units. Now I want to count the frequency of occurrence of samples in such a way that: The first sample should range from 0.01 to (0.01+0.1) square units and the total amount of such samples occurring. Next sample should range from 0.01+0.1 to (0.01+0.1)+0.1 square units and total amount of such samples occurring. This process should continue until the second range value becomes equal to or greater than

4.