model.py

import tensorflow as tf
from tensorflow.keras import layers, models, callbacks
from tensorflow.keras.preprocessing.image import ImageDataGenerator
import numpy as np
import matplotlib.pyplot as plt
import datetime
import os
import zipfile
from google.colab import files
from sklearn.metrics import classification_report, confusion_matrix
import seaborn as sns
from sklearn.utils import class_weight

print("TensorFlow version:", tf.__version__)


uploaded = files.upload()
zip_filename = list(uploaded.keys())[0]


extract_path = 'dataset'
with zipfile.ZipFile(zip_filename, 'r') as zip_ref:
    zip_ref.extractall(extract_path)


print("\nExtracted files:")
!ls {extract_path}
print("\nTrain folder contents:")
!ls {extract_path}/train


IMG_SIZE = (150, 150)
BATCH_SIZE = 32


train_datagen = ImageDataGenerator(
    rescale=1./255,
    rotation_range=40,
    width_shift_range=0.3,
    height_shift_range=0.3,
    shear_range=0.3,
    zoom_range=0.3,
    horizontal_flip=True,
    vertical_flip=True,
    brightness_range=[0.8, 1.2],
    validation_split=0.2,
    fill_mode='nearest'
)

train_generator = train_datagen.flow_from_directory(
    os.path.join(extract_path, 'train'),
    target_size=IMG_SIZE,
    batch_size=BATCH_SIZE,
    class_mode='binary',
    subset='training',
    shuffle=True
)

validation_generator = train_datagen.flow_from_directory(
    os.path.join(extract_path, 'train'),
    target_size=IMG_SIZE,
    batch_size=BATCH_SIZE,
    class_mode='binary',
    subset='validation',
    shuffle=True
)


class_weights = class_weight.compute_class_weight(
    'balanced',
    classes=np.unique(train_generator.classes),
    y=train_generator.classes
)
class_weights = dict(enumerate(class_weights))

class_names = list(train_generator.class_indices.keys())
print("\nDetected classes:", class_names)
print("Training samples:", train_generator.samples)
print("Validation samples:", validation_generator.samples)
print("Class weights:", class_weights)


def build_enhanced_model(input_shape):
    model = models.Sequential([
      
        layers.Conv2D(64, (3,3), activation='relu', padding='same', input_shape=input_shape),
        layers.BatchNormalization(),
        layers.Conv2D(64, (3,3), activation='relu', padding='same'),
        layers.BatchNormalization(),
        layers.MaxPooling2D((2,2)),
        layers.Dropout(0.3),
        
       
        layers.Conv2D(128, (3,3), activation='relu', padding='same'),
        layers.BatchNormalization(),
        layers.Conv2D(128, (3,3), activation='relu', padding='same'),
        layers.BatchNormalization(),
        layers.MaxPooling2D((2,2)),
        layers.Dropout(0.3),
        
        
        layers.Conv2D(256, (3,3), activation='relu', padding='same'),
        layers.BatchNormalization(),
        layers.Conv2D(256, (3,3), activation='relu', padding='same'),
        layers.BatchNormalization(),
        layers.MaxPooling2D((2,2)),
        layers.Dropout(0.4),
        
      
        layers.Flatten(),
        layers.Dense(512, activation='relu'),
        layers.BatchNormalization(),
        layers.Dropout(0.5),
        layers.Dense(1, activation='sigmoid')
    ])
    
    optimizer = tf.keras.optimizers.Adam(learning_rate=0.0001)
    
    model.compile(
        optimizer=optimizer,
        loss='binary_crossentropy',
        metrics=['accuracy', tf.keras.metrics.AUC(name='auc')]
    )
    return model

model = build_enhanced_model(input_shape=(IMG_SIZE[0], IMG_SIZE[1], 3))
model.summary()


log_dir = "logs/fit/" + datetime.datetime.now().strftime("%Y%m%d-%H%M%S")


callbacks = [
    callbacks.TensorBoard(log_dir=log_dir),
    callbacks.ReduceLROnPlateau(
        monitor='val_loss',
        factor=0.5,
        patience=3,
        min_lr=1e-7,
        verbose=1
    ),
    callbacks.ModelCheckpoint(
        'best_model.keras',
        monitor='val_auc',
        mode='max',
        save_best_only=True,
        save_weights_only=False,
        verbose=1
    )
]

print("\nStarting training for full 30 epochs...")
history = model.fit(
    train_generator,
    steps_per_epoch=train_generator.samples // BATCH_SIZE,
    epochs=30,
    validation_data=validation_generator,
    validation_steps=validation_generator.samples // BATCH_SIZE,
    callbacks=callbacks,
    class_weight=class_weights,
    verbose=1
)


print("\nTraining complete. Saving final model...")

model.save('final_model.keras')


history_df = pd.DataFrame(history.history)
history_df.to_csv('training_history.csv', index=False)


plt.figure(figsize=(12, 5))
plt.subplot(1, 2, 1)
plt.plot(history.history['accuracy'], label='Train Accuracy')
plt.plot(history.history['val_accuracy'], label='Validation Accuracy')
plt.title('Model Accuracy')
plt.ylabel('Accuracy')
plt.xlabel('Epoch')
plt.legend()

plt.subplot(1, 2, 2)
plt.plot(history.history['loss'], label='Train Loss')
plt.plot(history.history['val_loss'], label='Validation Loss')
plt.title('Model Loss')
plt.ylabel('Loss')
plt.xlabel('Epoch')
plt.legend()
plt.show()

val_preds = model.predict(validation_generator)
val_preds = (val_preds > 0.5).astype(int)


cm = confusion_matrix(validation_generator.classes, val_preds)
plt.figure(figsize=(6, 6))
sns.heatmap(cm, annot=True, fmt='d', cmap='Blues',
            xticklabels=class_names, yticklabels=class_names)
plt.title('Confusion Matrix')
plt.ylabel('True Label')
plt.xlabel('Predicted Label')
plt.show()


print("\nClassification Report:")
print(classification_report(validation_generator.classes, val_preds,
                           target_names=class_names))


converter = tf.lite.TFLiteConverter.from_keras_model(model)
tflite_model = converter.convert()
with open('cat_dog.tflite', 'wb') as f:
    f.write(tflite_model)

print("\nAll models saved successfully:")
print("- final_model.keras (model after all epochs)")
print("- best_model.keras (best validation AUC model)")
print("- cat_dog.tflite (TFLite version)")