1.什么是tensorflow?
TensorFlow名字的由来就是张量(Tensor)在计算图(Computational Graph)里的流动(Flow),如图。它的基础就是前面介绍的基于计算图的自动微分,除了自动帮你求梯度之外,它也提供了各种常见的操作(op,也就是计算图的节点),常见的损失函数,优化算法。
- TensorFlow 是一个用于研究和生产的开放源代码机器学习库。TensorFlow 提供了各种 API,可供初学者和专家在桌面、移动、网络和云端环境下进行开发。
- TensorFlow是采用数据流图(data flow graphs)来计算,所以首先我们得创建一个数据流流图,然后再将我们的数据(数据以张量(tensor)的形式存在)放在数据流图中计算. 节点(Nodes)在图中表示数学操作,图中的边(edges)则表示在节点间相互联系的多维数据数组, 即张量(tensor)。训练模型时tensor会不断的从数据流图中的一个节点flow到另一节点, 这就是TensorFlow名字的由来。 张量(Tensor):张量有多种. 零阶张量为 纯量或标量 (scalar) 也就是一个数值. 比如 [1],一阶张量为 向量 (vector), 比如 一维的 [1, 2, 3],二阶张量为 矩阵 (matrix), 比如 二维的 [[1, 2, 3],[4, 5, 6],[7, 8, 9]],以此类推, 还有 三阶 三维的 … 张量从流图的一端流动到另一端的计算过程。它生动形象地描述了复杂数据结构在人工神经网中的流动、传输、分析和处理模式。
在机器学习中,数值通常由4种类型构成: (1)标量(scalar):即一个数值,它是计算的最小单元,如“1”或“3.2”等。 (2)向量(vector):由一些标量构成的一维数组,如[1, 3.2, 4.6]等。 (3)矩阵(matrix):是由标量构成的二维数组。 (4)张量(tensor):由多维(通常)数组构成的数据集合,可理解为高维矩阵。
tensorflow的基本概念
- 图:描述了计算过程,Tensorflow用图来表示计算过程
- 张量:Tensorflow 使用tensor表示数据,每一个tensor是一个多维化的数组
- 操作:图中的节点为op,一个op获得/输入0个或者多个Tensor,执行并计算,产生0个或多个Tensor
- 会话:session tensorflow的运行需要再绘话里面运行
tensorflow写代码流程
- 定义变量占位符
- 根据数学原理写方程
- 定义损失函数cost
- 定义优化梯度下降 GradientDescentOptimizer
- session 进行训练,for循环
- 保存saver
2.环境准备
整合步骤
- 模型构建:首先,我们需要在TensorFlow中定义并训练深度学习模型。这可能涉及选择合适的网络结构、优化器和损失函数等。
- 训练数据准备:接下来,我们需要准备用于训练和验证模型的数据。这可能包括数据清洗、标注和预处理等步骤。
- REST API设计:为了与TensorFlow模型进行交互,我们需要在SpringBoot中创建一个REST API。这可以使用SpringBoot的内置功能来实现,例如使用Spring MVC或Spring WebFlux。
- 模型部署:在模型训练完成后,我们需要将其部署到SpringBoot应用中。为此,我们可以使用TensorFlow的Java API将模型导出为ONNX或SavedModel格式,然后在SpringBoot应用中加载并使用。
在整合过程中,有几个关键点需要注意。首先,防火墙设置可能会影响TensorFlow训练过程中的网络通信。确保你的防火墙允许TensorFlow访问其所需的网络资源,以免出现训练中断或模型性能下降的问题。其次,要关注版本兼容性。SpringBoot和TensorFlow都有各自的版本更新周期,确保在整合时使用兼容的版本可以避免很多不必要的麻烦。
模型下载
模型构建和模型训练这块设计到python代码,这里跳过,感兴趣的可以下载源代码自己训练模型,咱们直接下载训练好的模型
下载好了,解压放在/resources/inception_v3目录下
3.代码工程
实验目的
实现图片检测
pom.xml
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<parent>
<artifactId>springboot-demo</artifactId>
<groupId>com.et</groupId>
<version>1.0-SNAPSHOT</version>
</parent>
<modelVersion>4.0.0</modelVersion>
<artifactId>Tensorflow</artifactId>
<properties>
<maven.compiler.source>11</maven.compiler.source>
<maven.compiler.target>11</maven.compiler.target>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-autoconfigure</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.tensorflow</groupId>
<artifactId>tensorflow-core-platform</artifactId>
<version>0.5.0</version>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
</dependency>
<dependency>
<groupId>jmimemagic</groupId>
<artifactId>jmimemagic</artifactId>
<version>0.1.2</version>
</dependency>
<dependency>
<groupId>jakarta.platform</groupId>
<artifactId>jakarta.jakartaee-api</artifactId>
<version>9.0.0</version>
</dependency>
<dependency>
<groupId>commons-io</groupId>
<artifactId>commons-io</artifactId>
<version>2.16.1</version>
</dependency>
<dependency>
<groupId>org.springframework.restdocs</groupId>
<artifactId>spring-restdocs-mockmvc</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
</project>
controller
package com.et.tf.api;
import java.io.IOException;
import com.et.tf.service.ClassifyImageService;
import net.sf.jmimemagic.Magic;
import net.sf.jmimemagic.MagicMatch;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.CrossOrigin;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;
@RestController
@RequestMapping("/api")
public class AppController {
@Autowired
ClassifyImageService classifyImageService;
@PostMapping(value = "/classify")
@CrossOrigin(origins = "*")
public ClassifyImageService.LabelWithProbability classifyImage(@RequestParam MultipartFile file) throws IOException {
checkImageContents(file);
return classifyImageService.classifyImage(file.getBytes());
}
@RequestMapping(value = "/")
public String index() {
return "index";
}
private void checkImageContents(MultipartFile file) {
MagicMatch match;
try {
match = Magic.getMagicMatch(file.getBytes());
} catch (Exception e) {
throw new RuntimeException(e);
}
String mimeType = match.getMimeType();
if (!mimeType.startsWith("image")) {
throw new IllegalArgumentException("Not an image type: " + mimeType);
}
}
}
service
package com.et.tf.service;
import jakarta.annotation.PreDestroy;
import java.util.Arrays;
import java.util.List;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Service;
import org.tensorflow.Graph;
import org.tensorflow.Output;
import org.tensorflow.Session;
import org.tensorflow.Tensor;
import org.tensorflow.ndarray.NdArrays;
import org.tensorflow.ndarray.Shape;
import org.tensorflow.ndarray.buffer.FloatDataBuffer;
import org.tensorflow.op.OpScope;
import org.tensorflow.op.Scope;
import org.tensorflow.proto.framework.DataType;
import org.tensorflow.types.TFloat32;
import org.tensorflow.types.TInt32;
import org.tensorflow.types.TString;
import org.tensorflow.types.family.TType;
//Inspired from https://github.com/tensorflow/tensorflow/blob/master/tensorflow/java/src/main/java/org/tensorflow/examples/LabelImage.java
@Service
@Slf4j
public class ClassifyImageService {
private final Session session;
private final List<String> labels;
private final String outputLayer;
private final int W;
private final int H;
private final float mean;
private final float scale;
public ClassifyImageService(
Graph inceptionGraph, List<String> labels, @Value("${tf.outputLayer}") String outputLayer,
@Value("${tf.image.width}") int imageW, @Value("${tf.image.height}") int imageH,
@Value("${tf.image.mean}") float mean, @Value("${tf.image.scale}") float scale
) {
this.labels = labels;
this.outputLayer = outputLayer;
this.H = imageH;
this.W = imageW;
this.mean = mean;
this.scale = scale;
this.session = new Session(inceptionGraph);
}
public LabelWithProbability classifyImage(byte[] imageBytes) {
long start = System.currentTimeMillis();
try (Tensor image = normalizedImageToTensor(imageBytes)) {
float[] labelProbabilities = classifyImageProbabilities(image);
int bestLabelIdx = maxIndex(labelProbabilities);
LabelWithProbability labelWithProbability =
new LabelWithProbability(labels.get(bestLabelIdx), labelProbabilities[bestLabelIdx] * 100f, System.currentTimeMillis() - start);
log.debug(String.format(
"Image classification [%s %.2f%%] took %d ms",
labelWithProbability.getLabel(),
labelWithProbability.getProbability(),
labelWithProbability.getElapsed()
)
);
return labelWithProbability;
}
}
private float[] classifyImageProbabilities(Tensor image) {
try (Tensor result = session.runner().feed("input", image).fetch(outputLayer).run().get(0)) {
final Shape resultShape = result.shape();
final long[] rShape = resultShape.asArray();
if (resultShape.numDimensions() != 2 || rShape[0] != 1) {
throw new RuntimeException(
String.format(
"Expected model to produce a [1 N] shaped tensor where N is the number of labels, instead it produced one with shape %s",
Arrays.toString(rShape)
));
}
int nlabels = (int) rShape[1];
FloatDataBuffer resultFloatBuffer = result.asRawTensor().data().asFloats();
float[] dst = new float[nlabels];
resultFloatBuffer.read(dst);
return dst;
}
}
private int maxIndex(float[] probabilities) {
int best = 0;
for (int i = 1; i < probabilities.length; ++i) {
if (probabilities[i] > probabilities[best]) {
best = i;
}
}
return best;
}
private Tensor normalizedImageToTensor(byte[] imageBytes) {
try (Graph g = new Graph();
TInt32 batchTensor = TInt32.scalarOf(0);
TInt32 sizeTensor = TInt32.vectorOf(H, W);
TFloat32 meanTensor = TFloat32.scalarOf(mean);
TFloat32 scaleTensor = TFloat32.scalarOf(scale);
) {
GraphBuilder b = new GraphBuilder(g);
//Tutorial python here: https://github.com/tensorflow/tensorflow/tree/master/tensorflow/examples/label_image
// Some constants specific to the pre-trained model at:
// https://storage.googleapis.com/download.tensorflow.org/models/inception_v3_2016_08_28_frozen.pb.tar.gz
//
// - The model was trained with images scaled to 299x299 pixels.
// - The colors, represented as R, G, B in 1-byte each were converted to
// float using (value - Mean)/Scale.
// Since the graph is being constructed once per execution here, we can use a constant for the
// input image. If the graph were to be re-used for multiple input images, a placeholder would
// have been more appropriate.
final Output input = b.constant("input", TString.tensorOfBytes(NdArrays.scalarOfObject(imageBytes)));
final Output output =
b.div(
b.sub(
b.resizeBilinear(
b.expandDims(
b.cast(b.decodeJpeg(input, 3), DataType.DT_FLOAT),
b.constant("make_batch", batchTensor)
),
b.constant("size", sizeTensor)
),
b.constant("mean", meanTensor)
),
b.constant("scale", scaleTensor)
);
try (Session s = new Session(g)) {
return s.runner().fetch(output.op().name()).run().get(0);
}
}
}
static class GraphBuilder {
final Scope scope;
GraphBuilder(Graph g) {
this.g = g;
this.scope = new OpScope(g);
}
Output div(Output x, Output y) {
return binaryOp("Div", x, y);
}
Output sub(Output x, Output y) {
return binaryOp("Sub", x, y);
}
Output resizeBilinear(Output images, Output size) {
return binaryOp("ResizeBilinear", images, size);
}
Output expandDims(Output input, Output dim) {
return binaryOp("ExpandDims", input, dim);
}
Output cast(Output value, DataType dtype) {
return g.opBuilder("Cast", "Cast", scope).addInput(value).setAttr("DstT", dtype).build().output(0);
}
Output decodeJpeg(Output contents, long channels) {
return g.opBuilder("DecodeJpeg", "DecodeJpeg", scope)
.addInput(contents)
.setAttr("channels", channels)
.build()
.output(0);
}
Output<? extends TType> constant(String name, Tensor t) {
return g.opBuilder("Const", name, scope)
.setAttr("dtype", t.dataType())
.setAttr("value", t)
.build()
.output(0);
}
private Output binaryOp(String type, Output in1, Output in2) {
return g.opBuilder(type, type, scope).addInput(in1).addInput(in2).build().output(0);
}
private final Graph g;
}
@PreDestroy
public void close() {
session.close();
}
@Data
@NoArgsConstructor
@AllArgsConstructor
public static class LabelWithProbability {
private String label;
private float probability;
private long elapsed;
}
}
application.yaml
tf:
frozenModelPath: inception-v3/inception_v3_2016_08_28_frozen.pb
labelsPath: inception-v3/imagenet_slim_labels.txt
outputLayer: InceptionV3/Predictions/Reshape_1
image:
width: 299
height: 299
mean: 0
scale: 255
logging.level.net.sf.jmimemagic: WARN
spring:
servlet:
multipart:
max-file-size: 5MB
Application.java
package com.et.tf;
import java.io.IOException;
import java.nio.charset.StandardCharsets;
import java.util.List;
import java.util.stream.Collectors;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.io.IOUtils;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.Bean;
import org.springframework.core.io.ClassPathResource;
import org.springframework.core.io.FileSystemResource;
import org.springframework.core.io.Resource;
import org.tensorflow.Graph;
import org.tensorflow.proto.framework.GraphDef;
@SpringBootApplication
@Slf4j
public class Application {
public static void main(String[] args) {
SpringApplication.run(Application.class, args);
}
@Bean
public Graph tfModelGraph(@Value("${tf.frozenModelPath}") String tfFrozenModelPath) throws IOException {
Resource graphResource = getResource(tfFrozenModelPath);
Graph graph = new Graph();
graph.importGraphDef(GraphDef.parseFrom(graphResource.getInputStream()));
log.info("Loaded Tensorflow model");
return graph;
}
private Resource getResource(@Value("${tf.frozenModelPath}") String tfFrozenModelPath) {
Resource graphResource = new FileSystemResource(tfFrozenModelPath);
if (!graphResource.exists()) {
graphResource = new ClassPathResource(tfFrozenModelPath);
}
if (!graphResource.exists()) {
throw new IllegalArgumentException(String.format("File %s does not exist", tfFrozenModelPath));
}
return graphResource;
}
@Bean
public List<String> tfModelLabels(@Value("${tf.labelsPath}") String labelsPath) throws IOException {
Resource labelsRes = getResource(labelsPath);
log.info("Loaded model labels");
return IOUtils.readLines(labelsRes.getInputStream(), StandardCharsets.UTF_8).stream()
.map(label -> label.substring(label.contains(":") ? label.indexOf(":") + 1 : 0)).collect(Collectors.toList());
}
}
4.测试
启动 Spring Boot应用程序
测试图片分类
访问http://127.0.0.1:8080/,上传一张图片,点击分类
5.引用