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models.py
590 lines (537 loc) · 21 KB
/
models.py
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from .. import utils as U
from ..imports import *
from .wrn import create_wide_residual_network
PRETRAINED_RESNET50 = "pretrained_resnet50"
PRETRAINED_MOBILENET = "pretrained_mobilenet"
PRETRAINED_MOBILENETV3 = "pretrained_mobilenetv3"
PRETRAINED_INCEPTION = "pretrained_inception"
PRETRAINED_EFFICIENTNETB1 = "pretrained_efficientnetb1"
PRETRAINED_EFFICIENTNETB7 = "pretrained_efficientnetb7"
RESNET50 = "resnet50"
MOBILENET = "mobilenet"
MOBILENETV3 = "mobilenetv3"
INCEPTION = "inception"
EFFICIENTNETB1 = "efficientnetb1"
EFFICIENTNETB7 = "efficientnetb7"
CNN = "default_cnn"
WRN22 = "wrn22"
PRETRAINED_MODELS = [
PRETRAINED_RESNET50,
PRETRAINED_MOBILENET,
PRETRAINED_MOBILENETV3,
PRETRAINED_INCEPTION,
PRETRAINED_EFFICIENTNETB1,
PRETRAINED_EFFICIENTNETB7,
]
PREDEFINED_MODELS = PRETRAINED_MODELS + [
RESNET50,
MOBILENET,
MOBILENETV3,
INCEPTION,
EFFICIENTNETB1,
EFFICIENTNETB7,
]
IMAGE_CLASSIFIERS = {
PRETRAINED_RESNET50: "50-layer Residual Network (pretrained on ImageNet)",
RESNET50: "50-layer Resididual Network (randomly initialized) [https://arxiv.org/abs/1512.03385]",
PRETRAINED_MOBILENET: "MobileNet Neural Network (pretrained on ImageNet)",
MOBILENET: "MobileNet Neural Network (randomly initialized) [https://arxiv.org/abs/1704.04861]",
PRETRAINED_MOBILENETV3: "MobileNetV3-Small Neural Network (pretrained on ImageNet)",
MOBILENETV3: "MobileNetV3-Small Neural Network (randomly initialized) [https://arxiv.org/abs/1905.02244]",
PRETRAINED_INCEPTION: "Inception Version 3 (pretrained on ImageNet)",
INCEPTION: "Inception Version 3 (randomly initialized) [http://arxiv.org/abs/1512.00567]",
PRETRAINED_EFFICIENTNETB1: "EfficientNet-B1 Neural Network (pretrained on ImageNet)",
EFFICIENTNETB1: "EfficientNet-B1 Neural Network (pretrained on ImageNet) [https://arxiv.org/abs/1905.11946]",
PRETRAINED_EFFICIENTNETB7: "EfficientNet-B7 Neural Network (pretrained on ImageNet)",
EFFICIENTNETB7: "EfficientNet-B7 Neural Network (pretrained on ImageNet) [https://arxiv.org/abs/1905.11946]",
WRN22: "22-layer Wide Residual Network (randomly initialized)",
CNN: "a default LeNet-like Convolutional Neural Network",
}
def print_image_classifiers():
for k, v in IMAGE_CLASSIFIERS.items():
print("%s: %s" % (k, v))
def print_image_regression_models():
for k, v in IMAGE_CLASSIFIERS.items():
print("%s: %s" % (k, v))
def pretrained_datagen(data, name):
if not data or not U.is_iter(data):
return
idg = data.image_data_generator
if name == PRETRAINED_RESNET50:
idg.preprocessing_function = keras.applications.resnet50.preprocess_input
idg.ktrain_preproc = "resnet50"
idg.rescale = None
idg.featurewise_center = False
idg.samplewise_center = False
idg.featurewise_std_normalization = False
idg.samplewise_std_normalization = False
idg.zca_whitening = False
elif name == PRETRAINED_MOBILENET:
idg.preprocessing_function = keras.applications.mobilenet.preprocess_input
idg.ktrain_preproc = "mobilenet"
idg.rescale = None
idg.featurewise_center = False
idg.samplewise_center = False
idg.featurewise_std_normalization = False
idg.samplewise_std_normalization = False
idg.zca_whitening = False
elif name == PRETRAINED_MOBILENETV3:
idg.preprocessing_function = keras.applications.mobilenet_v3.preprocess_input
idg.ktrain_preproc = "mobilenetv3"
idg.rescale = None
idg.featurewise_center = False
idg.samplewise_center = False
idg.featurewise_std_normalization = False
idg.samplewise_std_normalization = False
idg.zca_whitening = False
elif name == PRETRAINED_INCEPTION:
idg.preprocessing_function = keras.applications.inception_v3.preprocess_input
idg.ktrain_preproc = "inception"
idg.rescale = None
idg.featurewise_center = False
idg.samplewise_center = False
idg.featurewise_std_normalization = False
idg.samplewise_std_normalization = False
idg.zca_whitening = False
elif name == PRETRAINED_EFFICIENTNETB1 or name == PRETRAINED_EFFICIENTNETB7:
idg.preprocessing_function = keras.applications.efficientnet.preprocess_input
idg.ktrain_preproc = "efficientnet"
idg.rescale = None
idg.featurewise_center = False
idg.samplewise_center = False
idg.featurewise_std_normalization = False
idg.samplewise_std_normalization = False
idg.zca_whitening = False
return
def image_classifier(
name,
train_data,
val_data=None,
freeze_layers=None,
metrics=None,
optimizer_name=U.DEFAULT_OPT,
multilabel=None,
pt_fc=[],
pt_ps=[],
verbose=1,
):
"""
```
Returns a pre-defined/pre-trained model ready to be trained/fine-tuned
for multi-class classification. By default, all layers are
trainable/unfrozen.
Args:
name (string): one of model shown on ktrain.vision.print_image_classifiers
train_data (image.Iterator): train data. Note: Will be manipulated here!
val_data (image.Iterator): validation data. Note: Will be manipulated here!
freeze_layers (int): number of beginning layers to make untrainable
If None, then all layers except new Dense layers
will be frozen/untrainable.
metrics (list): metrics to use
metrics(list): List of metrics to use. If None: 'accuracy' is used for binar/multiclass,
'binary_accuracy' is used for multilabel classification, and 'mae' is used for regression
optimizer_name(str|obj): name of Keras optimizer (e.g., 'adam', 'sgd') or instance of keras Optimizer
multilabel(bool): If True, model will be build to support
multilabel classification (labels are not mutually exclusive).
If False, binary/multiclassification model will be returned.
If None, multilabel status will be inferred from data.
pt_fc (list of ints): number of hidden units in extra Dense layers
before final Dense layer of pretrained model.
Only takes effect if name in PRETRAINED_MODELS
pt_ps (list of floats): dropout probabilities to use before
each extra Dense layer in pretrained model.
Only takes effect if name in PRETRAINED_MODELS
verbose (int): verbosity
Return:
model(Model): the compiled model ready to be fine-tuned/trained
```
"""
return image_model(
name,
train_data,
val_data=val_data,
freeze_layers=freeze_layers,
metrics=metrics,
optimizer_name=optimizer_name,
multilabel=multilabel,
pt_fc=pt_fc,
pt_ps=pt_ps,
verbose=verbose,
)
def image_regression_model(
name,
train_data,
val_data=None,
freeze_layers=None,
metrics=["mae"],
optimizer_name=U.DEFAULT_OPT,
pt_fc=[],
pt_ps=[],
verbose=1,
):
"""
```
Returns a pre-defined/pre-trained model ready to be trained/fine-tuned
for multi-class classification. By default, all layers are
trainable/unfrozen.
Args:
name (string): one of model shown on ktrain.vision.print_image_regression_models
train_data (image.Iterator): train data. Note: Will be manipulated here!
val_data (image.Iterator): validation data. Note: Will be manipulated here!
freeze_layers (int): number of beginning layers to make untrainable
If None, then all layers except new Dense layers
will be frozen/untrainable.
metrics (list): metrics to use
optimizer_name(str): name of Keras optimizer (e.g., 'adam', 'sgd')
multilabel(bool): If True, model will be build to support
multilabel classificaiton (labels are not mutually exclusive).
If False, binary/multiclassification model will be returned.
If None, multilabel status will be inferred from data.
pt_fc (list of ints): number of hidden units in extra Dense layers
before final Dense layer of pretrained model.
Only takes effect if name in PRETRAINED_MODELS
pt_ps (list of floats): dropout probabilities to use before
each extra Dense layer in pretrained model.
Only takes effect if name in PRETRAINED_MODELS
verbose (int): verbosity
Return:
model(Model): the compiled model ready to be fine-tuned/trained
```
"""
return image_model(
name,
train_data,
val_data=val_data,
freeze_layers=freeze_layers,
metrics=metrics,
optimizer_name=optimizer_name,
multilabel=False,
pt_fc=pt_fc,
pt_ps=pt_ps,
verbose=verbose,
)
def image_model(
name,
train_data,
val_data=None,
freeze_layers=None,
metrics=None,
optimizer_name=U.DEFAULT_OPT,
multilabel=None,
pt_fc=[],
pt_ps=[],
verbose=1,
):
"""
```
Returns a pre-defined/pre-trained model ready to be trained/fine-tuned
for multi-class classification or regression. By default, all layers are
trainable/unfrozen.
Args:
name (string): one of model shown on ktrain.vision.print_image_classifiers
train_data (image.Iterator): train data. Note: Will be manipulated here!
val_data (image.Iterator): validation data. Note: Will be manipulated here!
freeze_layers (int): number of beginning layers to make untrainable
If None, then all layers except new Dense layers
will be frozen/untrainable.
metrics(list): List of metrics to use. If None: 'accuracy' is used for binar/multiclass,
'binary_accuracy' is used for multilabel classification, and 'mae' is used for regression
optimizer_name(str|obj): name of Keras optimizer (e.g., 'adam', 'sgd') or instance of Keras optimizer
multilabel(bool): If True, model will be build to support
multilabel classificaiton (labels are not mutually exclusive).
If False, binary/multiclassification model will be returned.
If None, multilabel status will be inferred from data.
pt_fc (list of ints): number of hidden units in extra Dense layers
before final Dense layer of pretrained model.
Only takes effect if name in PRETRAINED_MODELS
pt_ps (list of floats): dropout probabilities to use before
each extra Dense layer in pretrained model.
Only takes effect if name in PRETRAINED_MODELS
verbose (int): verbosity
Return:
model(Model): the compiled model ready to be fine-tuned/trained
```
"""
# arg check
U.data_arg_check(train_data=train_data, train_required=True)
if name not in list(IMAGE_CLASSIFIERS.keys()):
raise ValueError("Unknown or unsupported model: %s" % (name))
if not U.is_iter(train_data):
raise ValueError(
"train_data must be an Keras iterator "
+ "(e.g., DirectoryIterator, DataframIterator, "
+ "NumpyArrayIterator) - please use the ktrain.data.images_from* "
+ "functions"
)
# check for MobileNetV3
if name in [PRETRAINED_MOBILENETV3, MOBILENETV3] and not HAS_MOBILENETV3:
raise ValueError(
f"You chose {name}, but it does not appear to be available in your version of TensorFlow."
)
# set pretrained flag
pretrained = True if name in PRETRAINED_MODELS else False
# adjust freeze_layers with warning
if not pretrained and freeze_layers is not None and freeze_layers > 0:
warnings.warn(
"Only pretrained models (e.g., pretrained_resnet50) support freeze_layers. "
+ "Setting freeze_layers to 0. Use one of the following models if"
+ "desiring a model pretrained on ImageNet: %s" % (PRETRAINED_MODELS)
)
freeze_layers = 0
if pretrained and val_data is None:
raise ValueError(
"val_data is required if selecting a pretrained model, "
+ "as normalization scheme will be altered."
)
# adjust the data augmentation based on model selected
if pretrained:
pretrained_datagen(train_data, name)
pretrained_datagen(val_data, name)
U.vprint(
"The normalization scheme has been changed for use with a %s" % (name)
+ " model. If you decide to use a different model, please reload your"
+ " dataset with a ktrain.vision.data.images_from* function.\n",
verbose=verbose,
)
# determine if multilabel
if multilabel is None:
multilabel = U.is_multilabel(train_data)
is_regression = False
if not multilabel and len(train_data[0][-1].shape) == 1:
is_regression = True
# set metrics
if is_regression and metrics is None:
metrics = ["mae"]
elif multilabel and metrics is None:
metrics = ["binary_accuracy"]
elif metrics is None:
metrics = ["accuracy"]
# set loss and acivations
loss_func = "categorical_crossentropy"
activation = "softmax"
if multilabel:
loss_func = "binary_crossentropy"
activation = "sigmoid"
elif is_regression:
loss_func = "mse"
activation = None
U.vprint("Is Multi-Label? %s" % (multilabel), verbose=verbose)
U.vprint("Is Regression? %s" % (is_regression), verbose=verbose)
# determine number of classes and shape
num_classes = 1 if is_regression else U.nclasses_from_data(train_data)
input_shape = U.shape_from_data(train_data)
# ------------
# build model
# ------------
model = build_visionmodel(
name,
num_classes,
input_shape=input_shape,
freeze_layers=freeze_layers,
activation=activation,
pt_fc=pt_fc,
pt_ps=pt_ps,
)
model.compile(optimizer=optimizer_name, loss=loss_func, metrics=metrics)
return model
def build_visionmodel(
name,
num_classes,
input_shape=(224, 224, 3),
freeze_layers=2,
activation="softmax",
pt_fc=[],
pt_ps=[],
):
if name in PREDEFINED_MODELS:
model = build_predefined(
name,
num_classes,
input_shape=input_shape,
freeze_layers=freeze_layers,
activation=activation,
pt_fc=pt_fc,
pt_ps=pt_ps,
)
elif name == CNN:
model = build_cnn(num_classes, input_shape=input_shape, activation=activation)
elif name == WRN22:
model = create_wide_residual_network(
input_shape,
nb_classes=num_classes,
N=3,
k=6,
dropout=0.00,
activation=activation,
verbose=0,
)
else:
raise ValueError("Unknown model: %s" % (name))
U.vprint("%s model created." % (name))
return model
def build_cnn(num_classes, input_shape=(28, 28, 1), activation="softmax"):
model = keras.models.Sequential()
model.add(
keras.layers.Conv2D(
32,
kernel_size=(3, 3),
activation="relu",
kernel_initializer="he_normal",
input_shape=input_shape,
)
)
model.add(
keras.layers.Conv2D(
32, kernel_size=(3, 3), activation="relu", kernel_initializer="he_normal"
)
)
model.add(keras.layers.MaxPooling2D((2, 2)))
model.add(keras.layers.Dropout(0.20))
model.add(
keras.layers.Conv2D(
64,
(3, 3),
activation="relu",
padding="same",
kernel_initializer="he_normal",
)
)
model.add(
keras.layers.Conv2D(
64,
(3, 3),
activation="relu",
padding="same",
kernel_initializer="he_normal",
)
)
model.add(keras.layers.MaxPooling2D(pool_size=(2, 2)))
model.add(keras.layers.Dropout(0.25))
model.add(
keras.layers.Conv2D(
128,
(3, 3),
activation="relu",
padding="same",
kernel_initializer="he_normal",
)
)
model.add(keras.layers.Dropout(0.25))
model.add(keras.layers.Flatten())
model.add(keras.layers.Dense(128, activation="relu"))
model.add(keras.layers.BatchNormalization())
model.add(keras.layers.Dropout(0.25))
model.add(keras.layers.Dense(num_classes, activation=activation))
return model
def build_predefined(
name,
num_classes,
input_shape=(224, 224, 3),
freeze_layers=None,
activation="softmax",
pt_fc=[],
pt_ps=[],
):
"""
```
Builds a pre-defined architecture supported in Keras.
Args:
name (str): one of ktrain.vision.model.PREDEFINED_MODELS
num_classes (int): # of classes
input_shape (tuple): the input shape including channels
freeze_layers (int): number of early layers to freeze.
Only takes effect if name in PRETRAINED_MODELS.
If None and name in PRETRAINED_MODELS,
all layers except the "custom head"
fully-connected (Dense) layers are frozen.
activation (str): name of the Keras activation to use in final layer
pt_fc (list of ints): number of hidden units in extra Dense layers
before final Dense layer of pretrained model
pt_ps (list of floats): dropout probabilities to use before
each extra Dense layer in pretrained model
```
"""
# default parameters
include_top = False
input_tensor = None
dropout = 0.5 # final dropout
# setup pretrained
weights = "imagenet" if name in PRETRAINED_MODELS else None
# setup the pretrained network
if name in [RESNET50, PRETRAINED_RESNET50]:
with warnings.catch_warnings():
warnings.simplefilter("ignore")
net = keras.applications.ResNet50(
include_top=include_top,
weights=weights,
input_tensor=input_tensor,
input_shape=input_shape,
)
elif name in [MOBILENET, PRETRAINED_MOBILENET]:
net = keras.applications.MobileNet(
include_top=include_top,
weights=weights,
input_tensor=input_tensor,
input_shape=input_shape,
)
elif name in [MOBILENETV3, PRETRAINED_MOBILENETV3]:
net = keras.applications.MobileNetV3Small(
include_top=include_top,
weights=weights,
input_tensor=input_tensor,
input_shape=input_shape,
)
elif name in [INCEPTION, PRETRAINED_INCEPTION]:
net = keras.applications.InceptionV3(
include_top=include_top,
weights=weights,
input_tensor=input_tensor,
input_shape=input_shape,
)
elif name in [EFFICIENTNETB1, PRETRAINED_EFFICIENTNETB1]:
net = keras.applications.EfficientNetB1(
include_top=include_top,
weights=weights,
input_tensor=input_tensor,
input_shape=input_shape,
)
elif name in [EFFICIENTNETB7, PRETRAINED_EFFICIENTNETB7]:
net = keras.applications.EfficientNetB7(
include_top=include_top,
weights=weights,
input_tensor=input_tensor,
input_shape=input_shape,
)
else:
raise ValueError("Unsupported model: %s" % (name))
if freeze_layers is None:
for layer in net.layers:
layer.trainable = False
x = net.output
x = keras.layers.Flatten()(x)
# xtra FCs in pretrained model
if name in PRETRAINED_MODELS:
if len(pt_fc) != len(pt_ps):
raise ValueError("size off xtra_fc must match size of fc_dropouts")
for i, fc in enumerate(pt_fc):
p = pt_ps[i]
fc_name = "fc%s" % (i)
if p is not None:
x = keras.layers.Dropout(p)(x)
x = keras.layers.Dense(
fc, activation="relu", kernel_initializer="he_normal", name=fc_name
)(x)
# final FC
x = keras.layers.Dropout(dropout)(x)
output_layer = keras.layers.Dense(
num_classes, activation=activation, name=activation
)(x)
model = keras.Model(inputs=net.input, outputs=output_layer)
if freeze_layers is not None:
# set certain earlier layers as non-trainable
for layer in model.layers[:freeze_layers]:
layer.trainable = False
for layer in model.layers[freeze_layers:]:
layer.trainable = True
# set optimizer, loss, and metrics and return model
return model