What a camera needs to see smashed dots on a corrugated preprint
You must see the centre of the dot. Do not call it when the image is out of focus. A steady sight needs about 3 pixels. If you cannot see it clearly, do not loosen the threshold.
To see smashed dots on a corrugated preprint, you must see the centre of the dot. Do not call it when the image is out of focus. If you cannot see it, change the light or the resolution first. Do not loosen the threshold first.
If you cannot see it, change the optics first
The dot centre goes white, and a ring is squeezed out around it. If the image cannot separate them at all, moving the threshold only paints the barcode and the product name solid red. You must see the centre of the dot. Do not call it when the image is out of focus.
Optics
| Need | Enough looks like | Not enough looks like |
|---|---|---|
| You must see the centre of the dot. Do not call it when the image is out of focus. | The dot centre goes white, and a ring is squeezed out around it. | Only a blurry circle left |
| About 3 pixels across | Shows up steadily | Comes and goes, and you still write that it can be detected |
| Barcode and product name in the field of view | The critical spot is seen | Only the decorative edge is lit |
Try it on a sample
- Confirm the image can separate it: The dot centre goes white, and a ring is squeezed out around it.
- Count about how many pixels it spans.
- If you cannot see it clearly, change the light or the focus. Do not change the threshold.
