blakeblackshear.frigate/frigate/util/classification.py
Nicolas Mowen 1c75ff59f1 Classification Model UI (#18571)
* Setup basic training structure

* Build out route

* Handle model configs

* Add image fetch APIs

* Implement model training screen with dataset selection

* Implement viewing of training images

* Adjust directories

* Implement viewing of images

* Add support for deleting images

* Implement full deletion

* Implement classification model training

* Improve naming

* More renaming

* Improve layout

* Reduce logging

* Cleanup
2025-08-16 10:20:33 -05:00

115 lines
3.5 KiB
Python

"""Util for classification models."""
import logging
import os
import cv2
import numpy as np
import tensorflow as tf
from tensorflow.keras import layers, models, optimizers
from tensorflow.keras.applications import MobileNetV2
from tensorflow.keras.preprocessing.image import ImageDataGenerator
from frigate.const import CLIPS_DIR, MODEL_CACHE_DIR
BATCH_SIZE = 16
EPOCHS = 50
LEARNING_RATE = 0.001
@staticmethod
def generate_representative_dataset_factory(dataset_dir: str):
def generate_representative_dataset():
image_paths = []
for root, dirs, files in os.walk(dataset_dir):
for file in files:
if file.lower().endswith((".jpg", ".jpeg", ".png")):
image_paths.append(os.path.join(root, file))
for path in image_paths[:300]:
img = cv2.imread(path)
img = cv2.cvtColor(img, cv2.COLOR_BGR2RGB)
img = cv2.resize(img, (224, 224))
img_array = np.array(img, dtype=np.float32) / 255.0
img_array = img_array[None, ...]
yield [img_array]
return generate_representative_dataset
@staticmethod
def train_classification_model(model_name: str) -> bool:
"""Train a classification model."""
dataset_dir = os.path.join(CLIPS_DIR, model_name, "dataset")
model_dir = os.path.join(MODEL_CACHE_DIR, model_name)
num_classes = len(
[
d
for d in os.listdir(dataset_dir)
if os.path.isdir(os.path.join(dataset_dir, d))
]
)
tf.get_logger().setLevel(logging.ERROR)
# Start with imagenet base model with 35% of channels in each layer
base_model = MobileNetV2(
input_shape=(224, 224, 3),
include_top=False,
weights="imagenet",
alpha=0.35,
)
base_model.trainable = False # Freeze pre-trained layers
model = models.Sequential(
[
base_model,
layers.GlobalAveragePooling2D(),
layers.Dense(128, activation="relu"),
layers.Dropout(0.3),
layers.Dense(num_classes, activation="softmax"),
]
)
model.compile(
optimizer=optimizers.Adam(learning_rate=LEARNING_RATE),
loss="categorical_crossentropy",
metrics=["accuracy"],
)
# create training set
datagen = ImageDataGenerator(rescale=1.0 / 255, validation_split=0.2)
train_gen = datagen.flow_from_directory(
dataset_dir,
target_size=(224, 224),
batch_size=BATCH_SIZE,
class_mode="categorical",
subset="training",
)
# write labelmap
class_indices = train_gen.class_indices
index_to_class = {v: k for k, v in class_indices.items()}
sorted_classes = [index_to_class[i] for i in range(len(index_to_class))]
with open(os.path.join(model_dir, "labelmap.txt"), "w") as f:
for class_name in sorted_classes:
f.write(f"{class_name}\n")
# train the model
model.fit(train_gen, epochs=EPOCHS, verbose=0)
# convert model to tflite
converter = tf.lite.TFLiteConverter.from_keras_model(model)
converter.optimizations = [tf.lite.Optimize.DEFAULT]
converter.representative_dataset = generate_representative_dataset_factory(
dataset_dir
)
converter.target_spec.supported_ops = [tf.lite.OpsSet.TFLITE_BUILTINS_INT8]
converter.inference_input_type = tf.uint8
converter.inference_output_type = tf.uint8
tflite_model = converter.convert()
# write model
with open(os.path.join(model_dir, "model.tflite"), "wb") as f:
f.write(tflite_model)