monkeyshichi / segmentation_models

Segmentation models with pretrained backbones. Keras.

Segmentation Models

Segmentation models is python library with Neural Networks for Image Segmentation based on Keras (Tensorflow) framework.

The main features of this library are:

• High level API (just two lines to create NN)
• 4 models architectures for binary and multi class segmentation (including legendary Unet)
• 25 available backbones for each architecture
• All backbones have pre-trained weights for faster and better convergence

Table of Contents

• Quick start
• Simple training pipeline
• Models and Backbones
• Installation
• Documentation
• Change log
• Citing
• License

Quick start

Since the library is built on the Keras framework, created segmentaion model is just a Keras Model, which can be created as easy as:

from segmentation_models import Unet

model = Unet()

Depending on the task, you can change the network architecture by choosing backbones with fewer or more parameters and use pretrainded weights to initialize it:

model = Unet('resnet34', encoder_weights='imagenet')

Change number of output classes in the model (choose your case):

# binary segmentation (this parameters are default when you call Unet('resnet34')
model = Unet('resnet34', classes=1, activation='sigmoid')

# multiclass segmentation with non overlapping class masks (your classes + background)
model = Unet('resnet34', classes=3, activation='softmax')

# multiclass segmentation with independent overlapping/non-overlapping class masks
model = Unet('resnet34', classes=3, activation='sigmoid')

Change input shape of the model:

# if you set input channels not equal to 3, you have to set encoder_weights=None
# how to handle such case with encoder_weights='imagenet' described in docs
model = Unet('resnet34', input_shape=(None, None, 6), encoder_weights=None)

Simple training pipeline

from segmentation_models import Unet
from segmentation_models.backbones import get_preprocessing
from segmentation_models.losses import bce_jaccard_loss
from segmentation_models.metrics import iou_score

BACKBONE = 'resnet34'
preprocess_input = get_preprocessing(BACKBONE)

# load your data
x_train, y_train, x_val, y_val = load_data(...)

# preprocess input
x_train = preprocess_input(x_train)
x_val = preprocess_input(x_val)

# define model
model = Unet(BACKBONE, encoder_weights='imagenet')
model.compile('Adam', loss=bce_jaccard_loss, metrics=[iou_score])

# fit model
# if you use data generator use model.fit_generator(...) instead of model.fit(...)
# more about `fit_generator` here: https://keras.io/models/sequential/#fit_generator
model.fit(
    x=x_train,
    y=y_train,
    batch_size=16,
    epochs=100,
    validation_data=(x_val, y_val),
)

Same manimulations can be done with Linknet, PSPNet and FPN. For more detailed information about models API and use cases Read the Docs.

Models and Backbones

Models

• Unet
• FPN
• Linknet
• PSPNet

Unet	Linknet

PSPNet	FPN

Backbones

Type	Names
VGG	'vgg16' 'vgg19'
ResNet	'resnet18' 'resnet34' 'resnet50' 'resnet101' 'resnet152'
SE-ResNet	'seresnet18' 'seresnet34' 'seresnet50' 'seresnet101' 'seresnet152'
ResNeXt	'resnext50' 'resnext101'
SE-ResNeXt	'seresnext50' 'seresnext101'
SENet154	'senet154'
DenseNet	'densenet121' 'densenet169' 'densenet201'
Inception	'inceptionv3' 'inceptionresnetv2'
MobileNet	'mobilenet' 'mobilenetv2'

All backbones have weights trained on 2012 ILSVRC ImageNet dataset (encoder_weights='imagenet').

Installation

Requirements

1. Python 3.5+
2. Keras >= 2.2.0
3. Keras Application >= 1.0.7
4. Image Classifiers == 0.2.0
5. Tensorflow 1.9 (tested)

Pip package

$ pip install segmentation-models

Latest version

$ pip install git+https://github.com/qubvel/segmentation_models

Documentation

Latest documentation is avaliable on Read the Docs

Change Log

To see important changes between versions look at CHANGELOG.md

Citing

@misc{Yakubovskiy:2019,
  Author = {Pavel Yakubovskiy},
  Title = {Segmentation Models},
  Year = {2019},
  Publisher = {GitHub},
  Journal = {GitHub repository},
  Howpublished = {\url{https://github.com/qubvel/segmentation_models}}
}

License

Project is distributed under MIT Licence.