5x5_1000
5x5_1000 holds 1000 markers of
5×5 bits. In OpenCV it is
cv2.aruco.DICT_5X5_1000.
The numbers
| OpenCV name | cv2.aruco.DICT_5X5_1000 |
| Bits in a marker | 5 × 5 = 25 |
| Markers available | 1000, with IDs 0 to 999 |
| Printed width | 7 cells, border included |
| Bits the decoder repairs | 2 |
| Cell size on a 100 mm marker | 14.3 mm |
| Pixels wanted in the image | 84 (floor 28) |
| Range for a 100 mm marker | about 2.0 m |
Range assumes a camera 1920 px wide, 60 degree horizontal field of view, which is a focal length of about 1663 pixels, and a marker seen straight on.
A smaller dictionary is tougher
5x5_1000 repairs 2 bits. 5x5_100 holds the same markers but repairs 3. If you need 100 markers or fewer, prefer it.
When to use it
Five bit markers are a middle setting: noticeably tougher than four bit markers, and still readable well beyond arm reach. With 1000 markers it covers a large fleet of tagged objects, at the cost of a smaller repair budget.