Quantifying the effects of ground truth annotation quality on object detection and instance segmentation performance

Fully-supervised object detection and instance segmentation models have accomplished notable results on large-scale computer vision benchmark datasets. However, fully-supervised machine learning algorithms’ performances are immensely dependent on the quality of the training data. Preparing computer vision datasets for object detection and instance segmentation is a labor-intensive task requiring each instance in an image to be annotated. In practice, this often results in the quality of bounding box and polygon mask annotations being suboptimal. This paper quantifies empirically the ground truth annotation quality and COCO’s mean average precision (mAP) performance by introducing two separate noise measures, uniform and radial, into the ground truth bounding box and polygon mask annotations forthe COCO and Cityscapes datasets. Mask-RCNN models are trained on various levels of noise measures to investigate the performance of each level of noise. The results showed degradation of mAP as the level of both noise measures increased. For object detection and instance segmentation respectively, using the highest level of noise measure resulted in a mAP degradation of 0.185 & 0.208 for uniform noise with reductions of 0.118 & 0.064 for radial noise on the COCO dataset. As for the Cityscapes datasets, reductions of mAP performance of 0.147 & 0.142 for uniform noise and 0.101 & 0.033 for radial noise were recorded. Furthermore, a decrease in average precision is seen across all classes, with the exception of the class motorcycle. The reductions between classes vary, indicating the effects of annotation uncertainty are class-dependent.