4x4_100
4x4_100 holds 100 markers of
4×4 bits. In OpenCV it is
cv2.aruco.DICT_4X4_100.
The numbers
| OpenCV name | cv2.aruco.DICT_4X4_100 |
| Bits in a marker | 4 × 4 = 16 |
| Markers available | 100, with IDs 0 to 99 |
| Printed width | 6 cells, border included |
| Bits the decoder repairs | 1 |
| Cell size on a 100 mm marker | 16.7 mm |
| Pixels wanted in the image | 72 (floor 24) |
| Range for a 100 mm marker | about 2.3 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.
When to use it
Four bit markers have the widest cells at any printed size, so they read from the greatest distance and survive the most blur. They carry the least redundancy, so they are the easiest to misread.