import tensorflow as tf
from tensorflow.keras import layers, models

def build_autoencoder(input_shape):
    input_img = layers.Input(shape=input_shape)
    
    # Encoder
    x = layers.Conv2D(32, (3, 3), activation='relu', padding='same')(input_img)
    x = layers.MaxPooling2D((2, 2), padding='same')(x)
    x = layers.Conv2D(16, (3, 3), activation='relu', padding='same')(x)
    encoded = layers.MaxPooling2D((2, 2), padding='same')(x)

    # Decoder
    x = layers.Conv2D(16, (3, 3), activation='relu', padding='same')(encoded)
    x = layers.UpSampling2D((2, 2))(x)
    x = layers.Conv2D(32, (3, 3), activation='relu', padding='same')(x)
    x = layers.UpSampling2D((2, 2))(x)
    decoded = layers.Conv2D(1, (3, 3), activation='sigmoid', padding='same')(x)

    autoencoder = models.Model(input_img, decoded)
    autoencoder.compile(optimizer='adam', loss='mse')
    return autoencoder