Counting Objects

The following example shows how dry fruits on a conveyor belt are counted with the EyeVision software.

Starting position:


The goal is to count the Natsumes (a dried date) which are similar in shape and color and in addition touch each other. What's more is that the “Natsume” varies in surface, size and shape. For common image processing, to separate and count these fruits on a belt conveyor is not an easy task.




The dried dates are located on the x-coordinate on a belt conveyor. The dates are hurdled close together and touch each other. Also their position on the y-coordinate can vary. Those dates should be counted, while they are on the belt conveyor.

The illumination quest


The first challenge poses the search for the right illumination or respectively to get a high-contrast image. Furthermore also the shadows which the fruits cast should get eliminated as good as possible. Because if there is to much of a shadow left, the separation of the fruits from the background and from each other can get blurred and the best possible contour is needed for counting objects.

Illumination - Option 1

First, the dates should be brightly lit, while the belt conveyor should remain black.

The advantage: the contour of the fruits are highlighted better

The disadvantage: the wrinkles of the fruits' raisin-like surface are highlighted and therefore it will get difficult to separate the fruits


Illumination - Option 2

The second option was to illuminate the fruits in such a way that black dates would lie on a white belt conveyor. 

The advantage: it is now possible to harmonize the surface of the wrinkled fruits

The disadvantage: the contour of the objects is less visible and furthermore shadows emerge.

Goal attained

Various different filters were used to separate the similarly colored fruits.

The result is neatly separated and counted “Natsume” fruits, shown in the Camera Viewer of the EyeVision Software.