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How to use EffecientDet

In this example, we show how to train an EffecientDet model on the PETS dataset using either Fastai or Pytorch-Lightning training loop

# Installing IceVision
# !pip install icevision[all] icedata

# Imports
from icevision.all import *
import icedata

# Common part to all models

# Loading Data
data_dir = icedata.pets.load_data()

# Parser
class_map = icedata.pets.class_map()
parser = icedata.pets.parser(data_dir, class_map)
train_records, valid_records = parser.parse()
show_records(train_records[:3], ncols=3, class_map=class_map)

# Datasets
# Transforms
presize = 512
# For EffecientDet the size of the image has to be divisible by 128
size = 384
train_tfms = tfms.A.Adapter(
    [*tfms.A.aug_tfms(size=size, presize=presize), tfms.A.Normalize()]
)
valid_tfms = tfms.A.Adapter([*tfms.A.resize_and_pad(size), tfms.A.Normalize()])

train_ds = Dataset(train_records, train_tfms)
valid_ds = Dataset(valid_records, valid_tfms)

samples = [train_ds[0] for _ in range(3)]
show_samples(samples, ncols=3, class_map=class_map, denormalize_fn=denormalize_imagenet)

# EffecientDet Specific Part

# DataLoaders
train_dl = efficientdet.train_dl(train_ds, batch_size=16, num_workers=4, shuffle=True)
valid_dl = efficientdet.valid_dl(valid_ds, batch_size=16, num_workers=4, shuffle=False)
batch, samples = first(train_dl)
show_samples(
    samples[:6], class_map=class_map, ncols=3, denormalize_fn=denormalize_imagenet
)

# Model
model = efficientdet.model(
    model_name="tf_efficientdet_lite0", num_classes=len(class_map), img_size=size
)

# Define metrics
metrics = [COCOMetric(metric_type=COCOMetricType.bbox)]

# Fastai Learner
learn = efficientdet.fastai.learner(
    dls=[train_dl, valid_dl], model=model, metrics=metrics
)

# Fastai Training
learn.freeze()
learn.lr_find()

learn.fine_tune(10, 1e-2, freeze_epochs=1)

# Inference
# DataLoader
infer_dl = efficientdet.infer_dl(valid_ds, batch_size=8)
# Predict
samples, preds = efficientdet.predict_dl(model, infer_dl)
# Show samples
imgs = [sample["img"] for sample in samples]
show_preds(
    imgs=imgs[:6],
    preds=preds[:6],
    class_map=class_map,
    denormalize_fn=denormalize_imagenet,
    ncols=3,
)

# Installing IceVision
# !pip install icevision[all] icedata

# Imports
from icevision.all import *
import icedata

# Common part to all models

# Loading Data
data_dir = icedata.pets.load_data()

# Parser
class_map = icedata.pets.class_map()
parser = icedata.pets.parser(data_dir, class_map)
train_records, valid_records = parser.parse()
show_records(train_records[:3], ncols=3, class_map=class_map)

# Datasets
# Transforms
presize = 512
# EffecientDet requires the image size to be divisible by 128
size = 384
train_tfms = tfms.A.Adapter(
    [*tfms.A.aug_tfms(size=size, presize=presize), tfms.A.Normalize()]
)
valid_tfms = tfms.A.Adapter([*tfms.A.resize_and_pad(size), tfms.A.Normalize()])

train_ds = Dataset(train_records, train_tfms)
valid_ds = Dataset(valid_records, valid_tfms)

samples = [train_ds[0] for _ in range(3)]
show_samples(samples, ncols=3, class_map=class_map, denormalize_fn=denormalize_imagenet)

# EffecientDet Specific Part

# DataLoaders
train_dl = efficientdet.train_dl(train_ds, batch_size=16, num_workers=4, shuffle=True)
valid_dl = efficientdet.valid_dl(valid_ds, batch_size=16, num_workers=4, shuffle=False)
batch, samples = first(train_dl)
show_samples(
    samples[:6], class_map=class_map, ncols=3, denormalize_fn=denormalize_imagenet
)

# Model
model = efficientdet.model(
    model_name="tf_efficientdet_lite0", num_classes=len(class_map), img_size=size
)

# Define metrics
metrics = [COCOMetric(metric_type=COCOMetricType.bbox)]

# Train using pytorch-lightning
class LightModel(faster_rcnn.lightning.ModelAdapter):
    def configure_optimizers(self):
        return SGD(self.parameters(), lr=1e-4)

light_model = LightModel(model, metrics=metrics)

trainer = pl.Trainer(max_epochs=10, gpus=1)
trainer.fit(light_model, train_dl, valid_dl)

# Inference
# DataLoader
infer_dl = efficientdet.infer_dl(valid_ds, batch_size=8)
# Predict
samples, preds = efficientdet.predict_dl(model, infer_dl)
# Show samples
imgs = [sample["img"] for sample in samples]
show_preds(
    imgs=imgs[:6],
    preds=preds[:6],
    class_map=class_map,
    denormalize_fn=denormalize_imagenet,
    ncols=3,
)