I am confused by the right answer of these two questions. The union area which includes the intersection area is correct in one question but is considered wrong in another question. Which is the correct one?
Both are correct.
The union is the total area enclosed by the outer perimeter.
It is 9 in the first graph, and 28 in the second graph.
The intersection is 1 in the first graph, and 4 in the second graph.
1/9 is the IOU for the first graph.
4/28 = 1/7 is the IOU for the second graph.
1 Like
Okay understood. Thank you for your response.
Right! The key point to notice is that the intersection area must be included only once in the union area. If you simply add the two areas of the individual rectangles (as you did in the first case), you are double counting the intersection.
1 Like