di+erent pretraining for Mask R-CNN, with a backbone pretrained on imagenet1, or with MS COCO pretraining. We train and evaluate on arti cial sheye images. Results demonstrate that the weights pretrained on MS COCO have good priors for dealing with sheye images. 13 Experiments Average Precision with 50%/75% threshold Average Precision Average Precision for small, medium and large objects 1O. Russakovsky et al. ImageNet Large Scale Visual Object Recognition Challenge, IJCV, 2015