Trying to train detectron2 - KeyError: 'p2'

Question

I have a json file with labeled images and I'm trying to train detectron2 to identify leaves in a picture of a tree. I keep getting this error:

Traceback (most recent call last):

  File "/home/aesa/steps.py", line 71, in <module>
    trainer = DefaultTrainer(cfg)
  File "/home/aesa/anaconda3/envs/detectron_env/lib/python3.10/site-packages/detectron2/engine/d                                                                                       efaults.py", line 376, in __init__
    model = self.build_model(cfg)
  File "/home/aesa/anaconda3/envs/detectron_env/lib/python3.10/site-packages/detectron2/engine/d                                                                                       efaults.py", line 514, in build_model
    model = build_model(cfg)
  File "/home/aesa/anaconda3/envs/detectron_env/lib/python3.10/site-packages/detectron2/modeling                                                                                       /meta_arch/build.py", line 22, in build_model
    model = META_ARCH_REGISTRY.get(meta_arch)(cfg)
  File "/home/aesa/anaconda3/envs/detectron_env/lib/python3.10/site-packages/detectron2/config/c                                                                                       onfig.py", line 189, in wrapped
    explicit_args = _get_args_from_config(from_config_func, *args, **kwargs)
  File "/home/aesa/anaconda3/envs/detectron_env/lib/python3.10/site-packages/detectron2/config/c                                                                                       onfig.py", line 245, in _get_args_from_config
    ret = from_config_func(*args, **kwargs)
  File "/home/aesa/anaconda3/envs/detectron_env/lib/python3.10/site-packages/detectron2/modeling                                                                                       /meta_arch/rcnn.py", line 76, in from_config
    "proposal_generator": build_proposal_generator(cfg, backbone.output_shape()),
  File "/home/aesa/anaconda3/envs/detectron_env/lib/python3.10/site-packages/detectron2/modeling                                                                                       /proposal_generator/build.py", line 24, in build_proposal_generator
    return PROPOSAL_GENERATOR_REGISTRY.get(name)(cfg, input_shape)
  File "/home/aesa/anaconda3/envs/detectron_env/lib/python3.10/site-packages/detectron2/config/c                                                                                       onfig.py", line 189, in wrapped
    explicit_args = _get_args_from_config(from_config_func, *args, **kwargs)
  File "/home/aesa/anaconda3/envs/detectron_env/lib/python3.10/site-packages/detectron2/config/c                                                                                       onfig.py", line 245, in _get_args_from_config
    ret = from_config_func(*args, **kwargs)
  File "/home/aesa/anaconda3/envs/detectron_env/lib/python3.10/site-packages/detectron2/modeling                                                                                       /proposal_generator/rpn.py", line 280, in from_config
    ret["anchor_generator"] = build_anchor_generator(cfg, [input_shape[f] for f in in_features])
  File "/home/aesa/anaconda3/envs/detectron_env/lib/python3.10/site-packages/detectron2/modeling                                                                                       /proposal_generator/rpn.py", line 280, in <listcomp>
    ret["anchor_generator"] = build_anchor_generator(cfg, [input_shape[f] for f in in_features])
KeyError: 'p2'

My code is:

import json
from detectron2.data import MetadataCatalog, DatasetCatalog


def load_data(t="train"):
    if t == "train":
        with open(".../train/_annotations.coco.json", 'r') as file:
            train = json.load(file)
        return train
    elif t == "val":
      with open(".../val.json", 'r') as file:
          val = json.load(file)
    return val

for d in ["train", "val"]:
    DatasetCatalog.register(d, lambda d=d: load_data(d))
    MetadataCatalog.get(d).set(thing_classes=["Leaf"])
metadata = MetadataCatalog.get("train")

from detectron2.config import get_cfg
from detectron2 import model_zoo

def custom_config():
    cfg = get_cfg()

    # get configuration from model_zoo
    cfg.merge_from_file(model_zoo.get_config_file("COCO-InstanceSegmentation/mask_rcnn_R_50_FPN_3x.yaml"))
    cfg.MODEL.WEIGHTS = model_zoo.get_checkpoint_url("COCO-InstanceSegmentation/mask_rcnn_R_50_FPN_3x.yaml")

    # Model
    cfg.MODEL.MASK_ON = True
    cfg.MODEL.ROI_HEADS.NUM_CLASSES = 1
    cfg.MODEL.BACKBONE.NAME = "build_resnet_backbone"
    cfg.MODEL.RESNETS.DEPTH = 34
    cfg.MODEL.RESNETS.RES2_OUT_CHANNELS = 64

    # Solver
    cfg.SOLVER.BASE_LR = 0.0002
    cfg.SOLVER.MAX_ITER = 40000
    cfg.SOLVER.STEPS = (20, 10000, 20000)
    cfg.SOLVER.gamma = 0.5
    cfg.SOLVER.IMS_PER_BATCH = 4

    # Test
    cfg.TEST.DETECTIONS_PER_IMAGE = 20

    # INPUT
    cfg.INPUT.MIN_SIZE_TRAIN = (800,)

    # DATASETS
    cfg.DATASETS.TEST = ('val',)
    cfg.DATASETS.TRAIN = ('train',)

    # DATASETS
    cfg.OUTPUT_DIR = "/train/"

    return cfg

from detectron2.data import MetadataCatalog, DatasetCatalog
from detectron2.engine import DefaultTrainer

if __name__ == '__main__':
    for d in ["train", "val"]:
        #DatasetCatalog.register(d, lambda d=d: load_data(d))
        MetadataCatalog.get(d).set(thing_classes=["Leaf"])

    metadata = MetadataCatalog.get("train")

    cfg = custom_config()

    trainer = DefaultTrainer(cfg)
    trainer.resume_or_load(resume=False)
    trainer.train()

I have tried reinstalling Detectron2 but it didn't solve the issue.

Answer 1

Had the same problem and after commenting cfg.MODEL.BACKBONE.NAME="build_resnet_backbone" line, it suddenly worked. This name was not in alignment with the chosen model.

Answer 2

To resolve the issue, you can modify the cfg configuration file by changing the values of cfg.MODEL.ROI_HEADS.NAME and cfg.MODEL.ROI_HEADS.IN_FEATURES. This will affect the ROI_Head field of the configuration and may help to resolve the issue.