What a camera needs to see a ring hickey on a pharma label
You must be able to see the centre of the ring. If it smears into one patch, you cannot tell it apart. If you cannot see it, change the light or the resolution first. Do not loosen the threshold first.
You must be able to see the centre of the ring. If it smears into one patch, you cannot tell it apart. 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
A white spot with fibre in the middle, or a ring of ink. If the picture cannot separate it at all, moving the threshold only paints the legal type and the barcode on the pharma label as a field of red. You must be able to see the centre of the ring. If it smears into one patch, you cannot tell it apart.
Optics
| Needed | Enough looks like | Not enough looks like |
|---|---|---|
| You must be able to see the centre of the ring. If it smears into one patch, you cannot tell it apart. | A white spot with fibre in the middle, or a ring of ink. | Only a blurred circle left |
| About 3 pixels across | It shows steadily | It comes and goes, yet you write that it can be detected |
| Legal type and the barcode are in the field of view | The critical place is seen | The light only hits the decoration edge |
Try it on a sample sheet
- Confirm the picture can separate this: A white spot with fibre in the middle, or a ring of ink.
- Count about how many pixels it covers.
- If you cannot see it clearly, change the light or the focus. Do not change the threshold.
