Where should you place the camera on an egg grading line?

What field of view does the camera need?

The field of view must show the whole egg for the whole pass, not just a moment of it. Vigiovo follows each egg from frame to frame and measures it three times, with at least half a radius of travel between measurements. An egg that appears only at the edge of the frame is not measured in full.

An egg touching the image border is marked unverified and is never graded. That protects against errors, but a tight field of view produces more unverified eggs. Leave a clear margin of image around the egg path.

• the whole egg fits in the frame, with a margin;
• no egg is cut by the image border at any point on its path;
• the visible stretch of belt is long enough for the three measurements.

Do eggs need to rotate in front of the camera?

A camera above the conveyor sees only the face of the egg turned towards it. If the egg does not rotate, the part of the shell facing down or sideways stays out of the image, and dirt or a crack on that part does not appear.

So an egg seen only in part should not be read as clean. The safest practice is to treat whatever was not seen in full as unverified, and to record that the measurement covers only the visible face.

How do you avoid glare and shadows?

Use diffuse, even light and keep the light source from reflecting directly off the shell. A reflection on the shell can look like dirt, so the lighting comes before any software setting.

Vigiovo excludes specular highlights from the dirt measurement, and on video it rejects an egg only when the defect shows up in 2 of 3 measurements, which removes glare that lasts a single frame. Exclusion does not replace good lighting. See lighting for egg inspection and glare and false dirty grades.

Where does the camera go relative to candling?

The camera goes before candling, on a stretch where eggs travel in a line with little contact between them. Touching eggs are split by segmentation, but when an outline is still unclear, the egg is marked unverified.

In line order, the camera sees the shell before the interior is examined. The comparison of placing the camera before or after candling is in camera before or after candling.

How do you know the placement is right?

The placement is right when almost every egg receives a class and unverified eggs are the exception. Many unverified eggs point to a problem with the field of view, the light or the spacing on the belt.

With Vigiovo, every decision comes with the class, the reason and the measurements used, which helps find the cause. If unverified eggs cluster at one point on the belt, the problem is in the set-up. For the figures by house, see dirty and cracked egg KPIs, and for the details of each measurement, how it works.

Frequently asked questions

Does the camera need to see the whole egg?

Yes, as far as possible. An egg that touches the image border is marked unverified and is not graded. So the field of view should cover the whole pass of the egg with a clear margin. An egg that does not rotate shows only one face, and the other faces stay unmeasured.

Can glare turn a clean egg into a dirty one?

It can. Direct light reflecting off the shell can look like a stain. Vigiovo excludes specular highlights from the dirt measurement, and on video it rejects an egg only when the defect shows up in 2 of 3 measurements, which removes glare that lasts a single frame.

Does a well placed camera replace candling?

No. Candling shows the inside of the egg, such as the air cell and the yolk, which a surface camera cannot see. The camera measures the shell and can remove dirty and visibly cracked eggs before candling, but it does not replace it.

Sources

1. Como o Vigiovo classifica ovos sem IA / How Vigiovo grades eggs without AI, Vigiovo