detectron2/configs/COCO-InstanceSegmentation/mask_rcnn_R_50_C4_3x.yaml

_BASE_: "../Base-RCNN-C4.yaml"
MODEL:
  WEIGHTS: "detectron2://ImageNetPretrained/MSRA/R-50.pkl"
  MASK_ON: True
  RESNETS:
    DEPTH: 50
SOLVER:
  STEPS: (210000, 250000)
  MAX_ITER: 270000