问题
I have trained a Mask RCNN network using PyTorch and am trying to use the obtained weights to predict the location of apples in an image..
I am using the dataset from this paper, and here is the github link to code being used
I am simply following the instructions as provided in the ReadMe file..
Here is the command i wrote in prompt (removed personal info)
python predict_rcnn.py --data_path "my_directory\datasets\apples-minneapple\detection" --output_file "my_directory\samples\apples\predictions" --weight_file "my_directory\samples\apples\weights\model_19.pth" --mrcnn
model_19.pth is the file with all the weights generated after the 19th epoch
Error is as follows:
Loading model
Traceback (most recent call last):
File "predict_rcnn.py", line 122, in <module>
main(args)
File "predict_rcnn.py", line 77, in main
model.load_state_dict(checkpoint['model'], strict=False)
KeyError: 'model'
I will paste predict_rcnn.py for convenience:
import os
import torch
import torch.utils.data
import torchvision
import numpy as np
from data.apple_dataset import AppleDataset
from torchvision.models.detection.faster_rcnn import FastRCNNPredictor
from torchvision.models.detection.mask_rcnn import MaskRCNNPredictor
import utility.utils as utils
import utility.transforms as T
######################################################
# Predict with either a Faster-RCNN or Mask-RCNN predictor
# using the MinneApple dataset
######################################################
def get_transform(train):
transforms = []
transforms.append(T.ToTensor())
if train:
transforms.append(T.RandomHorizontalFlip(0.5))
return T.Compose(transforms)
def get_maskrcnn_model_instance(num_classes):
# load an instance segmentation model pre-trained pre-trained on COCO
model = torchvision.models.detection.maskrcnn_resnet50_fpn(pretrained=False)
# get number of input features for the classifier
in_features = model.roi_heads.box_predictor.cls_score.in_features
# replace the pre-trained head with a new one
model.roi_heads.box_predictor = FastRCNNPredictor(in_features, num_classes)
# now get the number of input features for the mask classifier
in_features_mask = model.roi_heads.mask_predictor.conv5_mask.in_channels
hidden_layer = 256
# and replace the mask predictor with a new one
model.roi_heads.mask_predictor = MaskRCNNPredictor(in_features_mask, hidden_layer, num_classes)
return model
def get_frcnn_model_instance(num_classes):
# load an instance segmentation model pre-trained pre-trained on COCO
model = torchvision.models.detection.fasterrcnn_resnet50_fpn(pretrained=False)
# get number of input features for the classifier
in_features = model.roi_heads.box_predictor.cls_score.in_features
# replace the pre-trained head with a new one
model.roi_heads.box_predictor = FastRCNNPredictor(in_features, num_classes)
return model
def main(args):
num_classes = 2
device = args.device
# Load the model from
print("Loading model")
# Create the correct model type
if args.mrcnn:
model = get_maskrcnn_model_instance(num_classes)
else:
model = get_frcnn_model_instance(num_classes)
# Load model parameters and keep on CPU
checkpoint = torch.load(args.weight_file, map_location=device)
#checkpoint = torch.load(args.weight_file, map_location=lambda storage, loc: storage)
model.load_state_dict(checkpoint['model'], strict=False)
model.eval()
print("Creating data loaders")
dataset_test = AppleDataset(args.data_path, get_transform(train=False))
data_loader_test = torch.utils.data.DataLoader(dataset_test, batch_size=1,
shuffle=False, num_workers=1,
collate_fn=utils.collate_fn)
# Create output directory
base_path = os.path.dirname(args.output_file)
if not os.path.exists(base_path):
os.makedirs(base_path)
# Predict on bboxes on each image
f = open(args.output_file, 'a')
for image, targets in data_loader_test:
image = list(img.to(device) for img in image)
outputs = model(image)
for ii, output in enumerate(outputs):
img_id = targets[ii]['image_id']
img_name = data_loader_test.dataset.get_img_name(img_id)
print("Predicting on image: {}".format(img_name))
boxes = output['boxes'].detach().numpy()
scores = output['scores'].detach().numpy()
im_names = np.repeat(img_name, len(boxes), axis=0)
stacked = np.hstack((im_names.reshape(len(scores), 1), boxes.astype(int), scores.reshape(len(scores), 1)))
# File to write predictions to
np.savetxt(f, stacked, fmt='%s', delimiter=',', newline='\n')
if __name__ == "__main__":
import argparse
parser = argparse.ArgumentParser(description='PyTorch Detection')
parser.add_argument('--data_path', required=True, help='path to the data to predict on')
parser.add_argument('--output_file', required=True, help='path where to write the prediction outputs')
parser.add_argument('--weight_file', required=True, help='path to the weight file')
parser.add_argument('--device', default='cuda', help='device to use. Either cpu or cuda')
model = parser.add_mutually_exclusive_group(required=True)
model.add_argument('--frcnn', action='store_true', help='use a Faster-RCNN model')
model.add_argument('--mrcnn', action='store_true', help='use a Mask-RCNN model')
args = parser.parse_args()
main(args)
回答1:
There is no 'model' parameter in the saved checkpoint. If you look in train_rcnn.py:106:
torch.save(model.state_dict(), os.path.join(args.output_dir, 'model_{}.pth'.format(epoch)))
you see that they save just the model parameters. It should've been something like:
torch.save({
"model": model.state_dict(),
"optimizer": optimizer.state_dict(),
"lr_scheduler": lr_scheduler.state_dict()
}, os.path.join(args.output_dir, 'model_{}.pth'.format(epoch)))
so then after loading you get a dictionary with 'model', and the other parameters they appear to be wanting to keep.
This seems to be a bug in their code.
来源：https://stackoverflow.com/questions/60795375/unable-to-load-model-weights-while-predicting-using-pytorch