下面是一个基本的卷积神经网络(CNN)模型代码示例:
org.springframework.boot
spring-boot-starter-web
org.tensorflow
tensorflow
2.4.0
2.定义模型架构
public class CNNModel {
private static final int IMAGE_WIDTH = 28;
private static final int IMAGE_HEIGHT = 28;
private static final int NUM_CLASSES = 10;
private static final int NUM_FILTERS = 32;
private static final int FILTER_SIZE = 3;
private static final int STRIDE = 1;
private static final int NUM_UNITS = 128;
private Model model;
public CNNModel() {
model = Sequential.create();
// 第一层卷积层
model.add(Conv2d.create(NUM_FILTERS, FILTER_SIZE, FILTER_SIZE, 1, "same", Input.inputShape(IMAGE_HEIGHT, IMAGE_WIDTH, 1)));
model.add(ReLU.create());
model.add(MaxPool2d.create(2, 2, "valid"));
// 第二层卷积层
model.add(Conv2d.create(NUM_FILTERS, FILTER_SIZE, FILTER_SIZE, 1, "same"));
model.add(ReLU.create());
model.add(MaxPool2d.create(2, 2, "valid"));
// 平坦层
model.add(Flatten.create());
// 全连接层
model.add(Dense.create(NUM_UNITS));
model.add(ReLU.create());
// 输出层
model.add(Dense.create(NUM_CLASSES));
model.add(Softmax.create());
}
public Model getModel() {
return model;
}
}
3.加载数据集
public class DataLoader {
private static final String TRAIN_IMAGES_FILE = "train-images-idx3-ubyte.gz";
private static final String TRAIN_LABELS_FILE = "train-labels-idx1-ubyte.gz";
private static final String TEST_IMAGES_FILE = "t10k-images-idx3-ubyte.gz";
private static final String TEST_LABELS_FILE = "t10k-labels-idx1-ubyte.gz";
private static final int IMAGE_WIDTH = 28;
private static final int IMAGE_HEIGHT = 28;
public static DataSet loadTrainData() throws IOException {
String trainImagesPath = DataLoader.class.getClassLoader().getResource(TRAIN_IMAGES_FILE).getPath();
String trainLabelsPath = DataLoader.class.getClassLoader().getResource(TRAIN_LABELS_FILE).getPath();
MnistDataSetIterator trainIterator = new MnistDataSetIterator(128, true, 12345);
return trainIterator.next();
}
public static DataSet loadTestData() throws IOException {
String testImagesPath = DataLoader.class.getClassLoader().getResource(TEST_IMAGES_FILE).getPath();
String testLabelsPath = DataLoader.class.getClassLoader().getResource(TEST_LABELS_FILE).getPath();
MnistDataSetIterator testIterator = new MnistDataSetIterator(128, false, 12345);
return testIterator.next();
}
public static void saveImage(String filePath, INDArray image) {
BufferedImage bufferedImage = new BufferedImage(IMAGE_WIDTH, IMAGE_HEIGHT, BufferedImage.TYPE_BYTE_GRAY);
for (int i = 0; i < IMAGE_HEIGHT; i++) {
for (int j = 0; j < IMAGE_WIDTH; j++) {
int pixelValue = (int) (255 * image.getDouble(i, j));
bufferedImage.setRGB(j, i, new Color(pixelValue, pixelValue, pixelValue).getRGB());
}
}
try {
ImageIO.write(bufferedImage, "png", new File(filePath));
} catch (IOException e) {
e.printStackTrace();
}
}
}
4.训练和评估模型
@RestController
public class ModelController {
private static final String MODEL_FILE = "model/cnn.pb";
private CNNModel cnnModel = new CNNModel();
@PostMapping("/train")
public ResponseEntity trainModel() throws IOException {
DataSet trainData = DataLoader.loadTrainData();
DataSet testData = DataLoader.loadTestData();
// 数据预处理
trainData.normalize();
testData.normalize();
// 构建计算图
Model model = cnnModel.getModel();
model.compile(new Adam(), new LossSparseCategoricalCrossEntropy(), new Metric[]{new Accuracy()});
// 训练模型
model.fit(trainData);
// 评估模型
Evaluation evaluation = model.evaluate(testData);
System.out.println("Test loss: " + evaluation.getLoss());
System.out.println("Test accuracy: " + evaluation.getAccuracy());
// 保存模型
model.save(new File(MODEL_FILE), true);
return ResponseEntity.ok("Model trained and saved.");
}
@PostMapping("/predict")
public ResponseEntity predictImage(@RequestParam("image") MultipartFile imageFile) throws IOException {
// 读取图片
BufferedImage bufferedImage = ImageIO.read(imageFile.getInputStream());
INDArray image = Nd4j.create(bufferedImage.getHeight(), bufferedImage.getWidth());
for (int i = 0; i < bufferedImage.getHeight(); i++) {
for (int j = 0; j < bufferedImage.getWidth(); j++) {
int pixelValue = new Color(bufferedImage.getRGB(j, i)).getRed();
image.putScalar(i, j, pixelValue / 255.0);
}
}
// 加载模型
Model model = Model.importFrozenModel(new File(MODEL_FILE))
.setInputNames("conv2d_input")
.setOutputNames("Identity");
// 预处理图片
INDArray input = image.reshape(1, 28, 28, 1);
input.divi(255.0);
// 预测结果
INDArray output = model.predict(input);
int predictedLabel = Nd4j.argMax(output, 1).getInt(0);
return ResponseEntity.ok("Predicted label: " + predictedLabel);
}
}
5.Spring Boot应用程序
SpringBootApplication
public class Application {
public static void main(String[] args) {
SpringApplication.run(Application.class, args);
}
}
这只是一个简单的卷积神经网络模型实现示例,实际上要构建一个准确的CNN模型需要更多的调整和优化。此外,还需要处理各种安全问题,例如防止对模型进行攻击、保证模型的隐私性等。因此,建议在实际应用中使用成熟的深度学习框架,而不是从头开始编写自己的模型代码。