in inception.py [0:0]
def __init__(self,
output_blocks=[DEFAULT_BLOCK_INDEX],
resize_input=True,
normalize_input=True,
requires_grad=False,
use_fid_inception=True):
"""Build pretrained InceptionV3
Parameters
----------
output_blocks : list of int
Indices of blocks to return features of. Possible values are:
- 0: corresponds to output of first max pooling
- 1: corresponds to output of second max pooling
- 2: corresponds to output which is fed to aux classifier
- 3: corresponds to output of final average pooling
resize_input : bool
If true, bilinearly resizes input to width and height 299 before
feeding input to model. As the network without fully connected
layers is fully convolutional, it should be able to handle inputs
of arbitrary size, so resizing might not be strictly needed
normalize_input : bool
If true, scales the input from range (0, 1) to the range the
pretrained Inception network expects, namely (-1, 1)
requires_grad : bool
If true, parameters of the model require gradients. Possibly useful
for finetuning the network
use_fid_inception : bool
If true, uses the pretrained Inception model used in Tensorflow's
FID implementation. If false, uses the pretrained Inception model
available in torchvision. The FID Inception model has different
weights and a slightly different structure from torchvision's
Inception model. If you want to compute FID scores, you are
strongly advised to set this parameter to true to get comparable
results.
"""
super(InceptionV3, self).__init__()
self.resize_input = resize_input
self.normalize_input = normalize_input
self.output_blocks = sorted(output_blocks)
self.last_needed_block = max(output_blocks)
assert self.last_needed_block <= 3, \
'Last possible output block index is 3'
self.blocks = nn.ModuleList()
if use_fid_inception:
inception = fid_inception_v3()
else:
inception = sketch_inception_v3()
self.inception = inception
# Block 0: input to maxpool1
block0 = [
inception.Conv2d_1a_3x3,
inception.Conv2d_2a_3x3,
inception.Conv2d_2b_3x3,
nn.MaxPool2d(kernel_size=3, stride=2)
]
self.blocks.append(nn.Sequential(*block0))
# Block 1: maxpool1 to maxpool2
if self.last_needed_block >= 1:
block1 = [
inception.Conv2d_3b_1x1,
inception.Conv2d_4a_3x3,
nn.MaxPool2d(kernel_size=3, stride=2)
]
self.blocks.append(nn.Sequential(*block1))
# Block 2: maxpool2 to aux classifier
if self.last_needed_block >= 2:
block2 = [
inception.Mixed_5b,
inception.Mixed_5c,
inception.Mixed_5d,
inception.Mixed_6a,
inception.Mixed_6b,
inception.Mixed_6c,
inception.Mixed_6d,
inception.Mixed_6e,
]
self.blocks.append(nn.Sequential(*block2))
# Block 3: aux classifier to final avgpool
if self.last_needed_block >= 3:
block3 = [
inception.Mixed_7a,
inception.Mixed_7b,
inception.Mixed_7c,
nn.AdaptiveAvgPool2d(output_size=(1, 1))
]
self.blocks.append(nn.Sequential(*block3))
for param in self.parameters():
param.requires_grad = requires_grad