mmpretrain/mmcls/apis/inference.py

108 lines
3.8 KiB
Python

# Copyright (c) OpenMMLab. All rights reserved.
import warnings
import matplotlib.pyplot as plt
import mmcv
import numpy as np
import torch
from mmcv.parallel import collate, scatter
from mmcv.runner import load_checkpoint
from mmcls.datasets.pipelines import Compose
from mmcls.models import build_classifier
def init_model(config, checkpoint=None, device='cuda:0', options=None):
"""Initialize a classifier from config file.
Args:
config (str or :obj:`mmcv.Config`): Config file path or the config
object.
checkpoint (str, optional): Checkpoint path. If left as None, the model
will not load any weights.
options (dict): Options to override some settings in the used config.
Returns:
nn.Module: The constructed classifier.
"""
if isinstance(config, str):
config = mmcv.Config.fromfile(config)
elif not isinstance(config, mmcv.Config):
raise TypeError('config must be a filename or Config object, '
f'but got {type(config)}')
if options is not None:
config.merge_from_dict(options)
config.model.pretrained = None
model = build_classifier(config.model)
if checkpoint is not None:
map_loc = 'cpu' if device == 'cpu' else None
checkpoint = load_checkpoint(model, checkpoint, map_location=map_loc)
if 'CLASSES' in checkpoint.get('meta', {}):
model.CLASSES = checkpoint['meta']['CLASSES']
else:
from mmcls.datasets import ImageNet
warnings.simplefilter('once')
warnings.warn('Class names are not saved in the checkpoint\'s '
'meta data, use imagenet by default.')
model.CLASSES = ImageNet.CLASSES
model.cfg = config # save the config in the model for convenience
model.to(device)
model.eval()
return model
def inference_model(model, img):
"""Inference image(s) with the classifier.
Args:
model (nn.Module): The loaded classifier.
img (str/ndarray): The image filename or loaded image.
Returns:
result (dict): The classification results that contains
`class_name`, `pred_label` and `pred_score`.
"""
cfg = model.cfg
device = next(model.parameters()).device # model device
# build the data pipeline
if isinstance(img, str):
if cfg.data.test.pipeline[0]['type'] != 'LoadImageFromFile':
cfg.data.test.pipeline.insert(0, dict(type='LoadImageFromFile'))
data = dict(img_info=dict(filename=img), img_prefix=None)
else:
if cfg.data.test.pipeline[0]['type'] == 'LoadImageFromFile':
cfg.data.test.pipeline.pop(0)
data = dict(img=img)
test_pipeline = Compose(cfg.data.test.pipeline)
data = test_pipeline(data)
data = collate([data], samples_per_gpu=1)
if next(model.parameters()).is_cuda:
# scatter to specified GPU
data = scatter(data, [device])[0]
# forward the model
with torch.no_grad():
scores = model(return_loss=False, **data)
pred_score = np.max(scores, axis=1)[0]
pred_label = np.argmax(scores, axis=1)[0]
result = {'pred_label': pred_label, 'pred_score': float(pred_score)}
result['pred_class'] = model.CLASSES[result['pred_label']]
return result
def show_result_pyplot(model, img, result, fig_size=(15, 10)):
"""Visualize the classification results on the image.
Args:
model (nn.Module): The loaded classifier.
img (str or np.ndarray): Image filename or loaded image.
result (list): The classification result.
fig_size (tuple): Figure size of the pyplot figure.
"""
if hasattr(model, 'module'):
model = model.module
img = model.show_result(img, result, show=False)
plt.figure(figsize=fig_size)
plt.imshow(mmcv.bgr2rgb(img))
plt.show()