I am looking for a non-destructive and reliable method to estimate the yield (fruit production) of an olive tree before harvest. I am wondering whether it is possible to use photographs followed by an image analysis to determine the number of olives on the tree. I suspect that the contrast of colors between olives and leaves or branches is not high enough to perform an efficient image analysis (as for other fruit trees). In addition, I am wondering how many photographs (or branch sampling) would be needed to have a representative estimate of the olive production. Do you know other good ways of assessing olive yield?