基于tensorflow和NasNet的皮肤癌分类项目

数据来源

https://challenge.isic-archive.com/data/#2019

数据划分

写了个脚本划分

for line in open('ISIC/labels.csv').readlines()[1:]:
    split_line = line.split(',')
    img_file = split_line[0]
    benign_malign = split_line[1]
 
    # 0.8 for train, 0.1 for test, 0.1 for validation
    random_num = random.random()
 
    if random_num < 0.8:
        location = train
        train_examples += 1
 
    elif random_num < 0.9:
        location = validation
        validation_examples += 1
 
    else:
        location = test
        test_examples += 1
 
    if int(float(benign_malign)) == 0:
        shutil.copy(
            'ISIC/images/' + img_file + '.jpg',
            location + 'benign/' + img_file + '.jpg'
        )
 
    elif int(float(benign_malign)) == 1:
        shutil.copy(
            'ISIC/images/' + img_file + '.jpg',
            location + 'malignant/' + img_file + '.jpg'
        )
 
print(f'Number of training examples {train_examples}')
print(f'Number of test examples {test_examples}')
print(f'Number of validation examples {validation_examples}')

数据生成模块

train_datagen = ImageDataGenerator(
    rescale=1.0 / 255,
    rotation_range=15,
    zoom_range=(0.95, 0.95),
    horizontal_flip=True,
    vertical_flip=True,
    data_format='channels_last',
    dtype=tf.float32,
)
 
 
train_gen = train_datagen.flow_from_directory(
    'data/train/',
    target_size=(img_height, img_width),
    batch_size=batch_size,
    color_mode='rgb',
    class_mode='binary',
    shuffle=True,
    seed=123,
)

 模型加载和运行

由于数据量较大，本次使用NasNet, 来源于nasnet | Kaggle

# NasNet
model = keras.Sequential([
    hub.KerasLayer(r'C:\\Users\\32573\\Desktop\\tools\py\\cancer_classification_project\\saved_model',
                   trainable=True),
    layers.Dense(1, activation='sigmoid'),
])

model.compile(
    optimizer=keras.optimizers.Adam(3e-4),
    loss=[keras.losses.BinaryCrossentropy(from_logits=False)],
    metrics=['accuracy']
)
 
model.fit(
    train_gen,
    epochs=1,
    steps_per_epoch=train_examples // batch_size,
    validation_data=validation_gen,
    validation_steps=validation_examples // batch_size,
)

运行结果 

 模型其他评估指标

METRICS = [
    keras.metrics.BinaryAccuracy(name='accuracy'),
    keras.metrics.Precision(name='precision'),
    keras.metrics.Recall(name='Recall'),
    keras.metrics.AUC(name='AUC'),
]

 绘制roc图

def plot_roc(label, data):
    predictions = model.predict(data)
    fp, tp, _ = roc_curve(label, predictions)
 
    plt.plot(100*fp, 100*tp)
    plt.xlabel('False Positives [%]')
    plt.ylabel('True Positives [%]')
    plt.show()
 
 
test_labels = np.array([])
num_batches = 0
 
for _, y in test_gen:
    test_labels = np.append(test_labels, y)
    num_batches = 1
    if num_batches == math.ceil(test_examples / batch_size):
        break
 
plot_roc(test_labels, test_gen)