caltech数据集的标注里面，ignore是什么意思 about csp HOT 1 OPEN

quoting from Pedestrian Detection: A Benchmark CVPR 2009 Dollar et al,
the "ignore" regions are :
To evaluate performance on different subsets of the ground truth, we introduce the notion of ignore regions. Ground truth BBs selected to be ignored, denoted using BBig, need not be matched, however, matches are not considered mistakes either. E.g., to evaluate performance on unoccluded pedestrians, we set all BBs that contain occluded pedestrians to ignore. Matching proceeds as before, except BBdt matched to BBig do not count as true positives, and unmatched BBig do not count as a false negatives (matches to BBgt are therefore preferred). Note that setting a BB to ignore is not the same as removing that BB from the ground truth; in the latter case detections in the ignore regions would count as false positives.

from csp.