What camera resolution is enough to grade eggs?

What camera resolution is enough to grade eggs?

It depends less on the total number of pixels and more on how many pixels cover each egg and the smallest defect the line must separate. There is no universal value. Vigiovo's demonstration uses a 960 × 540 pixel video and a 1228 × 691 pixel still image; these are tested examples, not a requirement for your line.

The practical question is different: does the camera show the shell, the dirt and the finest crack that your grading must separate, and show them sharply?

What matters more: pixels per egg or total pixels?

Pixels per egg. A large image with small eggs in the frame can carry less detail per egg than a smaller image with large eggs. Because an egg's size in the image depends on distance and lens, what counts is the ratio between the egg and the defect.

In Vigiovo that ratio is explicit. A crack only counts if it is at least 0.35 r long, elongated (at least five times longer than it is wide) and at least 0.4 r deep into the shell. A line below these limits does not count as a crack, with any camera.

If an egg occupies few pixels, the smallest defect that can be measured also occupies few pixels, and precision drops.

How does the egg radius act as a ruler?

On the first frame, Vigiovo estimates the typical egg radius from isolated blobs. This reference radius, called r, is the unit for every limit: the minimum length of a crack, its depth, the area range of a typical egg and the shape limits.

That is why the same configuration works with cameras of different resolutions. Changing the camera changes the number of pixels per egg, but the configuration keeps describing the egg in proportions, not in pixels.

Why is the image shrunk before the outline is found?

Finding an egg's outline does not need much detail. Vigiovo shrinks the image until the egg radius is about 12 pixels, which cuts the pixels processed by a factor of 4 to 10.

Shrinking saves processing, but it does not create detail the camera did not capture. If an egg occupies few pixels, its finest crack also occupies few pixels and can disappear. So camera resolution still matters for small defects.

How do you choose the resolution for your line?

Before fixing the camera specification, run these checks with eggs from your own line:

1. Measure how many pixels the diameter of one egg covers in the frame the camera will produce, using the real distance and lens.
2. List the smallest defect the grading must catch, such as a visible crack or a small dirt mark on the shell.
3. Compare those two numbers with the limits in multiples of r, to check whether the defect covers enough pixels.
4. Test with dirty, cracked and normal eggs from your farm before deciding.
5. Check focus and lighting, because extra pixels do not correct a blurred image or one with glare.

Lighting also decides what the camera sees; see lighting for egg inspection. And no resolution lets an ordinary camera under normal light see hairline cracks, which appear only by candling or acoustic testing.

Frequently asked questions

Is there a minimum resolution for grading eggs?

There is no universal number. The right resolution is the one that shows the smallest defect in your grading sharply, with enough pixels across each egg. Test with real eggs from your farm and confirm that dirt, visible cracks and out-of-shape eggs appear clearly.

Does a higher-resolution camera see hairline cracks?

Not necessarily. Hairline cracks do not show under normal light, and an ordinary camera cannot see them from outside, whatever the resolution. They need candling or acoustic testing, and a camera complements those methods.

Why does Vigiovo measure in multiples of the egg radius?

Because the egg's size in the image depends on distance and lens. Measuring relative to the egg itself, the limits describe the proportion of the defect, and the same configuration works with cameras of different resolutions.

Sources

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