AI engineering glossary · Computer vision
What is intersection over union?
Intersection over union (also called IoU, Jaccard index): A measure of how much two boxes or masks overlap: IoU = area of overlap / area of union. It ranges from 0 (no overlap) to 1 (perfect match) and decides whether a detection counts as correct.
Intersection over union: an example
Two 10 x 10 boxes overlapping in a 5 x 10 region have IoU = 50 / (100 + 100 - 50) = 0.33.
Related terms
More Computer vision terms
- Mask R-CNN
- Max pooling
- Median filter
- Mixup
- MobileNet
- Morphological operations
- Non-maximum suppression
- Object detection
Where you learn it
Intersection over union is part of the AI Engineering Program, which teaches it with notes, a hands-on lab and an exam. The first lesson is free.