augment_images.py

import os
from PIL import Image
from tensorflow.keras.preprocessing.image import ImageDataGenerator

# Set paths
base_dir = 'data/chest_xray'
val_dir = os.path.join(base_dir, 'val')
normal_class_dir = os.path.join(val_dir, 'NORMAL')
pneumonia_class_dir = os.path.join(val_dir, 'PNEUMONIA')


def augment_images(class_directory, num_augmented_images):
    datagen = ImageDataGenerator(
        rescale=1. / 255,
        rotation_range=20,
        width_shift_range=0.2,
        height_shift_range=0.2,
        shear_range=0.2,
        zoom_range=0.2,
        horizontal_flip=True,
        fill_mode='nearest'
    )

    generator = datagen.flow_from_directory(
        directory=os.path.dirname(class_directory),  # Parent directory
        target_size=(150, 150),
        batch_size=1,
        class_mode=None,
        shuffle=False,
        classes=[os.path.basename(class_directory)]  # Specify class if using subdirectory
    )

    print(f"Found {generator.samples} images in {class_directory}")

    if generator.samples == 0:
        print("No images found in the directory.")
        return

    count = 0

    while count < num_augmented_images:
        try:
            img_batch = generator.__next__()  # Use __next__() to get image batch
            img = (img_batch[0] * 255).astype('uint8')  # Extract the first image in the batch
            img_pil = Image.fromarray(img)
            img_path = os.path.join(class_directory, f"augmented_{count}.png")
            img_pil.save(img_path)
            count += 1
        except StopIteration:
            print("No more images to generate.")
            break

    print(f"Total augmented images created: {count}")


# Number of augmented images to generate
num_augmented_images_normal = 2944 - 3875  # This should be a negative number since NORMAL is already balanced
num_augmented_images_pneumonia = 2944 - 1171  # To match the number of NORMAL images

# Generate augmented images for the NORMAL class
augment_images(normal_class_dir, max(num_augmented_images_normal, 0))

# Generate augmented images for the PNEUMONIA class
augment_images(pneumonia_class_dir, num_augmented_images_pneumonia)