NA
YA=
3.05 x 6.1l(m2) X 2 (trees)
where YE = Estimated yield by the machine vision system,
YA = Actual yield by hand harvesting.
Yield (Yimage) WaS calculated based on the number of fruits identified from the
image. Each image covered 1.7 m of the canopy lengthwise and the distance from the
camera to the canopy was 3.0 m. Yimage WaS calculated as
NP
Y~mg frurts-prxels
3. 0x 1.7 (m )
where NP = Number of fruits/plot estimated using the machine vision system.
3.9 Performance of the Fruit Counting Algorithm
An algorithm was developed using 25 calibration images and tested on the
remaining 329 validation images. In order to evaluate the performance of the algorithm,
fruits counted by the fruit counting algorithm should have been compared with the actual
number of fruits in the region covered in the image. Since it was very difficult to define
the boundary of each image and count the number of fruits in the grove, the images were
shown to three observers and the average of these three reading were taken as reference
for the fruit counting algorithm. This arrangement was made for manual counting
because there were variations in the total number of fruit perceived by human beings.
ErrorImage(%) WaS defined as percentage error between the number of fruits counted by
the machine vision algorithm and the average number of fruits counted manually.
MV~ M\~C
Errormage (%) = x1000
where