Files
fast-depth-tf/fast_depth_functional.py
Piv 870429c3ef Refactor fast-depth
Addresses the following:
 - Rename nnconv5 block to nnconv5
 - Add skip connections directly to nnconv5 block
 - Allow custom metrics, loss and optimizer (keep defaults that reflect original paper) to train
 - Correctly use nyu evaluation dataset only when no dataset is provided
2021-03-29 17:57:12 +10:30

205 lines
7.7 KiB
Python

import tensorflow as tf
import tensorflow.keras as keras
import tensorflow_datasets as tfds
"""
Unofficial tensorflow keras implementation of FastDepth (mobilenet_nnconv5).
PyTorch (official) Fast Depth Implementation: https://github.com/dwofk/fast-depth
"""
# Ripped from:
# https://forums.developer.nvidia.com/t/could-not-create-cudnn-handle-cudnn-status-alloc-failed/108261/4?u=mpivato4
# Seems to be an issue on windows so explicitly set gpu growth
def fix_windows_gpu():
"""
Fixes Windows GPU bug when attempting to allocate memory using cuDNN
"""
gpus = tf.config.experimental.list_physical_devices('GPU')
if gpus:
try:
# Currently, memory growth needs to be the same across GPUs
for gpu in gpus:
tf.config.experimental.set_memory_growth(gpu, True)
logical_gpus = tf.config.experimental.list_logical_devices('GPU')
print(len(gpus), "Physical GPUs,", len(
logical_gpus), "Logical GPUs")
except RuntimeError as e:
# Memory growth must be set before GPUs have been initialized
print(e)
def nnconv5(inputs,
out_channels,
block_id=1,
skip_connection=None):
x = keras.layers.DepthwiseConv2D(5, padding='same')(inputs)
x = keras.layers.BatchNormalization()(x)
x = keras.layers.ReLU(6.)(x)
x = keras.layers.Conv2D(out_channels, 1, padding='same')(x)
x = keras.layers.BatchNormalization()(x)
x = keras.layers.UpSampling2D()(x)
if skip_connection is not None:
x = keras.layers.Add()([x, skip_connection])
return keras.layers.ReLU(6., name='conv_pw_%d_relu' % block_id)(x)
def mobilenet_nnconv5(weights=None, shape=(224, 224, 3)):
"""
Replication of the FastDepth model in Tensorflow, using the keras Functional API
:param weights: Pretrained weights for MobileNet, defaults to None
:param shape: Input shape of the image, defaults to (224, 224, 3)
:return: FastDepth keras Model
"""
input = keras.layers.Input(shape=shape)
mobilenet = keras.applications.MobileNet(
input_shape=shape, input_tensor=input, include_top=False, weights=weights)
for layer in mobilenet.layers:
layer.trainable = True
# Fast depth decoder
x = nnconv5(mobilenet.output, 512, block_id=14)
x = nnconv5(x, 256, block_id=15, skip_connection=mobilenet.get_layer(
name="conv_pw_5_relu").output)
x = nnconv5(x, 128, block_id=16, skip_connection=mobilenet.get_layer(
name="conv_pw_3_relu").output)
x = nnconv5(x, 64, block_id=17, skip_connection=mobilenet.get_layer(
name="conv_pw_1_relu").output)
x = nnconv5(x, 32, block_id=18)
x = keras.layers.Conv2D(1, 1, padding='same')(x)
x = keras.layers.BatchNormalization()(x)
x = keras.layers.ReLU(6.)(x)
return keras.Model(inputs=input, outputs=x, name="fast_depth")
def delta1_metric(y_true, y_pred):
maxRatio = tf.maximum(y_pred / y_true, y_true / y_pred)
return tf.nn.moments(tf.cast(maxRatio < tf.convert_to_tensor(1.25), tf.float32), axes=None)[0]
def delta2_metric(y_true, y_pred):
maxRatio = tf.maximum(y_pred / y_true, y_true / y_pred)
return tf.nn.moments(tf.cast(maxRatio < tf.convert_to_tensor(1.25 ** 2), tf.float32), axes=None)[0]
def delta3_metric(y_true, y_pred):
maxRatio = tf.maximum(y_pred / y_true, y_true / y_pred)
return tf.nn.moments(tf.cast(maxRatio < tf.convert_to_tensor(1.25 ** 3), tf.float32), axes=None)[0]
def compile(model, optimiser=keras.optimizers.SGD(), loss=keras.losses.MeanSquaredError(), custom_metrics=None):
"""
Compile FastDepth model with relevant metrics
:param model: Model to compile
:param optimiser: Custom optimiser to use
:param loss: Loss function to use
:param include_metrics: Whether to include metrics (RMSE, MSE, a1,2,3)
"""
model.compile(optimizer=optimiser,
loss=loss,
metrics=[keras.metrics.RootMeanSquaredError(),
keras.metrics.MeanSquaredError(),
delta1_metric,
delta2_metric,
delta3_metric] if custom_metrics is None else custom_metrics)
def train(existing_model=None, pretrained_weights='imagenet', epochs=4, save_file=None, dataset=None):
"""
Compile, train and save (if a save file is specified) a Fast Depth model.
:param existing_model: Existing FastDepth model to train. None will create
:param pretrained_weights: Weights to use if existing_model is not specified. See keras.applications.MobileNet
weights parameter for options here.
:param epochs: Number of epochs to run for
:param save_file: File/directory to save to after training. By default the model won't be saved
:param dataset: Train dataset to use. By default will DOWNLOAD and use tensorflow nyu_v2 dataset
"""
if not existing_model:
existing_model = mobilenet_nnconv5(pretrained_weights)
compile(existing_model)
if not dataset:
dataset = load_nyu()
existing_model.fit(dataset, epochs=epochs)
if save_file:
existing_model.save(save_file)
return existing_model
def evaluate(compiled_model, dataset=None):
"""
Evaluate the model using rmse, delta1/2/3 metrics
:param compiled_model: Compiled, trained model to evaluate
:param dataset: Dataset for evaluation. Should be of format {'image': image, 'depth': label},
where label width/height matches image width/height.
Defaults to Tensorflow nyu_v2 evaluation split dataset (https://www.tensorflow.org/datasets/catalog/nyu_depth_v2)
"""
if dataset is None:
dataset = load_nyu_evaluate()
compiled_model.evaluate(dataset, verbose=1)
def forward(model, image):
"""
Propagate a single or batch of images through the model. Image(s) should be in format NHWC
:param model:
:param image:
:return:
"""
return model(crop_and_resize(image))
def load_model(file):
"""
Load previously trained FastDepth model from disk. Will include relevant metrics (custom objects)
:param file: File/directory to load the model from
:return:
"""
return keras.models.load_model(file, custom_objects={'delta1_metric': delta1_metric,
'delta2_metric': delta2_metric,
'delta3_metric': delta3_metric})
def crop_and_resize(x):
shape = tf.shape(x['depth'])
def layer():
return keras.Sequential([
keras.layers.experimental.preprocessing.CenterCrop(
shape[1], shape[2]),
keras.layers.experimental.preprocessing.Resizing(
224, 224, interpolation='nearest')
])
# Reshape label to 4d, can't use array unwrap as it's unsupported by tensorflow
return layer()(x['image']), layer()(tf.reshape(x['depth'], [shape[0], shape[1], shape[2], 1]))
def load_nyu():
"""
Load the nyu_v2 dataset train split. Will be downloaded to ../nyu
:return: nyu_v2 dataset builder
"""
builder = tfds.builder('nyu_depth_v2')
builder.download_and_prepare(download_dir='../nyu')
return builder \
.as_dataset(split='train', shuffle_files=True) \
.shuffle(buffer_size=1024) \
.batch(8) \
.map(lambda x: crop_and_resize(x))
def load_nyu_evaluate():
"""
Load the nyu_v2 dataset validation split. Will be downloaded to ../nyu
:return: nyu_v2 dataset builder
"""
builder = tfds.builder('nyu_depth_v2')
builder.download_and_prepare(download_dir='../nyu')
return builder.as_dataset(split='validation').batch(1).map(lambda x: crop_and_resize(x))
if __name__ == '__main__':
model = mobilenet_nnconv5()
model.summary()