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在C#下使用TensorFlow.NET訓練自己的資料集

今天,我結合代碼來詳細介紹如何使用 SciSharp STACK 的 TensorFlow.NET 來訓練CNN模型,該模型主要實作 圖像的分類 ,可以直接移植該代碼在 CPU 或 GPU 下使用,并針對你們自己本地的圖像資料集進行訓練和推理。TensorFlow.NET是基于 .NET Standard 架構的完整實作的TensorFlow,可以支援

.NET Framework

.NET CORE

, TensorFlow.NET 為廣大.NET開發者提供了完美的機器學習架構選擇。

SciSharp STACK:https://github.com/SciSharp

什麼是TensorFlow.NET?

TensorFlow.NET 是 SciSharp STACK

在C#下使用TensorFlow.NET訓練自己的資料集

開源社群團隊的貢獻,其使命是打造一個完全屬于.NET開發者自己的機器學習平台,特别對于C#開發人員來說,是一個“0”學習成本的機器學習平台,該平台內建了大量API和底層封裝,力圖使TensorFlow的Python代碼風格和程式設計習慣可以無縫移植到.NET平台,下圖是同樣TF任務的Python實作和C#實作的文法相似度對比,從中讀者基本可以略窺一二。

在C#下使用TensorFlow.NET訓練自己的資料集

由于TensorFlow.NET在.NET平台的優秀性能,同時搭配SciSharp的NumSharp、SharpCV、Pandas.NET、Keras.NET、Matplotlib.Net等子產品,可以完全脫離Python環境使用,目前已經被微軟ML.NET官方的底層算法內建,并被谷歌寫入TensorFlow官網教程推薦給全球開發者。

· SciSharp 産品結構

在C#下使用TensorFlow.NET訓練自己的資料集

· 微軟 ML.NET底層內建算法

在C#下使用TensorFlow.NET訓練自己的資料集

· 谷歌官方推薦.NET開發者使用

URL: https://www.tensorflow.org/versions/r2.0/api_docs

在C#下使用TensorFlow.NET訓練自己的資料集

項目說明

本文利用TensorFlow.NET建構簡單的圖像分類模型,針對工業現場的印刷字元進行單字元OCR識别,從工業相機擷取原始大尺寸的圖像,前期使用OpenCV進行圖像預處理和字元分割,提取出單個字元的小圖,送入TF進行推理,推理的結果按照順序組合成完整的字元串,傳回至主程式邏輯進行後續的生産線工序。

實際使用中,如果你們需要訓練自己的圖像,隻需要把訓練的檔案夾按照規定的順序替換成你們自己的圖檔即可。支援GPU或CPU方式,該項目的完整代碼在GitHub如下:

https://github.com/SciSharp/SciSharp-Stack-Examples/blob/master/src/TensorFlowNET.Examples/ImageProcessing/CnnInYourOwnData.cs

模型介紹

本項目的CNN模型主要由 2個卷積層&池化層 和 1個全連接配接層 組成,激活函數使用常見的Relu,是一個比較淺的卷積神經網絡模型。其中超參數之一"學習率",采用了自定義的動态下降的學習率,後面會有詳細說明。具體每一層的Shape參考下圖:

在C#下使用TensorFlow.NET訓練自己的資料集

資料集說明

為了模型測試的訓練速度考慮,圖像資料集主要節選了一小部分的OCR字元(X、Y、Z),資料集的特征如下:

· 分類數量:3 classes 【X/Y/Z】

· 圖像尺寸:Width 64 × Height 64

· 圖像通道:1 channel(灰階圖)

· 資料集數量:

o train:X - 384pcs ;Y - 384pcs ;Z - 384pcs

o validation:X - 96pcs ;Y - 96pcs ;Z - 96pcs

o test:X - 96pcs ;Y - 96pcs ;Z - 96pcs

· 其它說明:資料集已經經過 随機 翻轉/平移/縮放/鏡像 等預處理進行增強

· 整體資料集情況如下圖所示:

在C#下使用TensorFlow.NET訓練自己的資料集

在這裡插入圖檔描述

在C#下使用TensorFlow.NET訓練自己的資料集

在這裡插入圖檔描述

在C#下使用TensorFlow.NET訓練自己的資料集

代碼說明

環境設定

· .NET 架構:使用.NET Framework 4.7.2及以上,或者使用.NET CORE 2.2及以上

· CPU 配置:Any CPU 或 X64 皆可

· GPU 配置:需要自行配置好CUDA和環境變量,建議 CUDA v10.1,Cudnn v7.5

類庫和命名空間引用

1. 從NuGet安裝必要的依賴項,主要是SciSharp相關的類庫,如下圖所示:

注意事項:盡量安裝最新版本的類庫,CV須使用 SciSharp 的 SharpCV 友善内部變量傳遞

<PackageReference Include="Colorful.Console" Version="1.2.9" />
<PackageReference Include="Newtonsoft.Json" Version="12.0.3" />
<PackageReference Include="SciSharp.TensorFlow.Redist" Version="1.15.0" />
<PackageReference Include="SciSharp.TensorFlowHub" Version="0.0.5" />
<PackageReference Include="SharpCV" Version="0.2.0" />
<PackageReference Include="SharpZipLib" Version="1.2.0" />
<PackageReference Include="System.Drawing.Common" Version="4.7.0" />
<PackageReference Include="TensorFlow.NET" Version="0.14.0" />           

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2. 引用命名空間,包括 NumSharp、Tensorflow 和 SharpCV ;

using NumSharp;
 using NumSharp.Backends;
 using NumSharp.Backends.Unmanaged;
 using SharpCV;
 using System;
 using System.Collections;
 using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.Runtime.CompilerServices;
using Tensorflow;
using static Tensorflow.Binding;
using static SharpCV.Binding;
using System.Collections.Concurrent;
using System.Threading.Tasks;           

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主邏輯結構

主邏輯:

1. 準備資料

2. 建立計算圖

3. 訓練

4. 預測

public bool Run()
{
    PrepareData();
    BuildGraph();
 
   using (var sess = tf.Session())
   {
       Train(sess);
       Test(sess);
   }

   TestDataOutput();

   return accuracy_test > 0.98;
}           

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資料集載入

資料集下載下傳和解壓

· 資料集位址:

https://github.com/SciSharp/SciSharp-Stack-Examples/blob/master/data/data_CnnInYourOwnData.zip

· 資料集下載下傳和解壓代碼 ( 部分封裝的方法請參考 GitHub完整代碼 ):

·       string url = "https://github.com/SciSharp/SciSharp-Stack-Examples/blob/master/data/data_CnnInYourOwnData.zip";
·       Directory.CreateDirectory(Name);
·       Utility.Web.Download(url, Name, "data_CnnInYourOwnData.zip");
·       Utility.Compress.UnZip(Name + "\\data_CnnInYourOwnData.zip", Name);           

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字典建立

讀取目錄下的子檔案夾名稱,作為分類的字典,友善後面One-hot使用

private void FillDictionaryLabel(string DirPath)
 {
     string[] str_dir = Directory.GetDirectories(DirPath, "*", SearchOption.TopDirectoryOnly);
     int str_dir_num = str_dir.Length;
     if (str_dir_num > 0)
     {
         Dict_Label = new Dictionary<Int64, string>();
         for (int i = 0; i < str_dir_num; i++)
         {
             string label = (str_dir[i].Replace(DirPath + "\\", "")).Split('\\').First();
             Dict_Label.Add(i, label);
             print(i.ToString() + " : " + label);
         }
         n_classes = Dict_Label.Count;
     }
 }
           

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檔案List讀取和打亂

從檔案夾中讀取train、validation、test的list,并随機打亂順序。

  • 讀取目錄
ArrayFileName_Train = Directory.GetFiles(Name + "\\train", "*.*", SearchOption.AllDirectories);
ArrayLabel_Train = GetLabelArray(ArrayFileName_Train);
 
ArrayFileName_Validation = Directory.GetFiles(Name + "\\validation", "*.*", SearchOption.AllDirectories);
ArrayLabel_Validation = GetLabelArray(ArrayFileName_Validation);
 
ArrayFileName_Test = Directory.GetFiles(Name + "\\test", "*.*", SearchOption.AllDirectories);
ArrayLabel_Test = GetLabelArray(ArrayFileName_Test);
           

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  • 獲得标簽
private Int64[] GetLabelArray(string[] FilesArray)
{
    Int64[] ArrayLabel = new Int64[FilesArray.Length];
    for (int i = 0; i < ArrayLabel.Length; i++)
    {
        string[] labels = FilesArray[i].Split('\\');
        string label = labels[labels.Length - 2];
        ArrayLabel[i] = Dict_Label.Single(k => k.Value == label).Key;
    }
    return ArrayLabel;
}
           

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  • 随機亂序
public (string[], Int64[]) ShuffleArray(int count, string[] images, Int64[] labels)
{
    ArrayList mylist = new ArrayList();
    string[] new_images = new string[count];
    Int64[] new_labels = new Int64[count];
    Random r = new Random();
    for (int i = 0; i < count; i++)
    {
        mylist.Add(i);
    }
 
    for (int i = 0; i < count; i++)
    {
        int rand = r.Next(mylist.Count);
        new_images[i] = images[(int)(mylist[rand])];
        new_labels[i] = labels[(int)(mylist[rand])];
        mylist.RemoveAt(rand);
    }
    print("shuffle array list:" + count.ToString());
    return (new_images, new_labels);
}
           

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部分資料集預先載入

Validation/Test資料集和标簽一次性預先載入成NDArray格式。

private void LoadImagesToNDArray()
{
    //Load labels
    y_valid = np.eye(Dict_Label.Count)[new NDArray(ArrayLabel_Validation)];
    y_test = np.eye(Dict_Label.Count)[new NDArray(ArrayLabel_Test)];
    print("Load Labels To NDArray : OK!");
 
    //Load Images
    x_valid = np.zeros(ArrayFileName_Validation.Length, img_h, img_w, n_channels);
    x_test = np.zeros(ArrayFileName_Test.Length, img_h, img_w, n_channels);
    LoadImage(ArrayFileName_Validation, x_valid, "validation");
    LoadImage(ArrayFileName_Test, x_test, "test");
    print("Load Images To NDArray : OK!");
}

private void LoadImage(string[] a, NDArray b, string c)
{
    for (int i = 0; i < a.Length; i++)
    {
        b[i] = ReadTensorFromImageFile(a[i]);
        Console.Write(".");
    }
    Console.WriteLine();
    Console.WriteLine("Load Images To NDArray: " + c);
}

private NDArray ReadTensorFromImageFile(string file_name)
{
    using (var graph = tf.Graph().as_default())
    {
        var file_reader = tf.read_file(file_name, "file_reader");
        var decodeJpeg = tf.image.decode_jpeg(file_reader, channels: n_channels, name: "DecodeJpeg");
        var cast = tf.cast(decodeJpeg, tf.float32);
        var dims_expander = tf.expand_dims(cast, 0);
        var resize = tf.constant(new int[] { img_h, img_w });
        var bilinear = tf.image.resize_bilinear(dims_expander, resize);
        var sub = tf.subtract(bilinear, new float[] { img_mean });
        var normalized = tf.divide(sub, new float[] { img_std });
 
        using (var sess = tf.Session(graph))
        {
            return sess.run(normalized);
        }
    }
}           

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計算圖建構

建構CNN靜态計算圖,其中學習率每n輪Epoch進行1次遞減。

#region BuildGraph
public Graph BuildGraph()
{
    var graph = new Graph().as_default();
 
    tf_with(tf.name_scope("Input"), delegate
            {
                x = tf.placeholder(tf.float32, shape: (-1, img_h, img_w, n_channels), name: "X");
                y = tf.placeholder(tf.float32, shape: (-1, n_classes), name: "Y");
            });
 
    var conv1 = conv_layer(x, filter_size1, num_filters1, stride1, name: "conv1");
    var pool1 = max_pool(conv1, ksize: 2, stride: 2, name: "pool1");
    var conv2 = conv_layer(pool1, filter_size2, num_filters2, stride2, name: "conv2");
    var pool2 = max_pool(conv2, ksize: 2, stride: 2, name: "pool2");
    var layer_flat = flatten_layer(pool2);
    var fc1 = fc_layer(layer_flat, h1, "FC1", use_relu: true);
    var output_logits = fc_layer(fc1, n_classes, "OUT", use_relu: false);
 
    //Some important parameter saved with graph , easy to load later
    var img_h_t = tf.constant(img_h, name: "img_h");
    var img_w_t = tf.constant(img_w, name: "img_w");
    var img_mean_t = tf.constant(img_mean, name: "img_mean");
    var img_std_t = tf.constant(img_std, name: "img_std");
    var channels_t = tf.constant(n_channels, name: "img_channels");
 
    //learning rate decay
    gloabl_steps = tf.Variable(0, trainable: false);
    learning_rate = tf.Variable(learning_rate_base);
 
    //create train images graph
    tf_with(tf.variable_scope("LoadImage"), delegate
            {
                decodeJpeg = tf.placeholder(tf.@byte, name: "DecodeJpeg");
                var cast = tf.cast(decodeJpeg, tf.float32);
                var dims_expander = tf.expand_dims(cast, 0);
                var resize = tf.constant(new int[] { img_h, img_w });
                var bilinear = tf.image.resize_bilinear(dims_expander, resize);
                var sub = tf.subtract(bilinear, new float[] { img_mean });
                normalized = tf.divide(sub, new float[] { img_std }, name: "normalized");
            });
 
    tf_with(tf.variable_scope("Train"), delegate
            {
                tf_with(tf.variable_scope("Loss"), delegate
                        {
                            loss = tf.reduce_mean(tf.nn.softmax_cross_entropy_with_logits(labels: y, logits: output_logits), name: "loss");
                        });
 
                tf_with(tf.variable_scope("Optimizer"), delegate
                        {
                            optimizer = tf.train.AdamOptimizer(learning_rate: learning_rate, name: "Adam-op").minimize(loss, global_step: gloabl_steps);
                        });
 
                tf_with(tf.variable_scope("Accuracy"), delegate
                        {
                            var correct_prediction = tf.equal(tf.argmax(output_logits, 1), tf.argmax(y, 1), name: "correct_pred");
                            accuracy = tf.reduce_mean(tf.cast(correct_prediction, tf.float32), name: "accuracy");
                        });
 
                tf_with(tf.variable_scope("Prediction"), delegate
                        {
                            cls_prediction = tf.argmax(output_logits, axis: 1, name: "predictions");
                            prob = tf.nn.softmax(output_logits, axis: 1, name: "prob");
                        });
            });
    return graph;
}
 
/// <summary>
/// Create a 2D convolution layer
/// </summary>
/// <param name="x">input from previous layer</param>
/// <param name="filter_size">size of each filter</param>
/// <param name="num_filters">number of filters(or output feature maps)</param>
/// <param name="stride">filter stride</param>
/// <param name="name">layer name</param>
/// <returns>The output array</returns>
private Tensor conv_layer(Tensor x, int filter_size, int num_filters, int stride, string name)
{
    return tf_with(tf.variable_scope(name), delegate
                   {
 
                       var num_in_channel = x.shape[x.NDims - 1];
                       var shape = new[] { filter_size, filter_size, num_in_channel, num_filters };
                       var W = weight_variable("W", shape);
                       // var tf.summary.histogram("weight", W);
                       var b = bias_variable("b", new[] { num_filters });
                       // tf.summary.histogram("bias", b);
                       var layer = tf.nn.conv2d(x, W,
                                                strides: new[] { 1, stride, stride, 1 },
                                                padding: "SAME");
                       layer += b;
                       return tf.nn.relu(layer);
                   });
}
 
/// <summary>
/// Create a max pooling layer
/// </summary>
/// <param name="x">input to max-pooling layer</param>
/// <param name="ksize">size of the max-pooling filter</param>
/// <param name="stride">stride of the max-pooling filter</param>
/// <param name="name">layer name</param>
/// <returns>The output array</returns>
private Tensor max_pool(Tensor x, int ksize, int stride, string name)
{
    return tf.nn.max_pool(x,
                          ksize: new[] { 1, ksize, ksize, 1 },
                          strides: new[] { 1, stride, stride, 1 },
                          padding: "SAME",
                          name: name);
}
 
/// <summary>
/// Flattens the output of the convolutional layer to be fed into fully-connected layer
/// </summary>
/// <param name="layer">input array</param>
/// <returns>flattened array</returns>
private Tensor flatten_layer(Tensor layer)
{
    return tf_with(tf.variable_scope("Flatten_layer"), delegate
                   {
                       var layer_shape = layer.TensorShape;
                       var num_features = layer_shape[new Slice(1, 4)].size;
                       var layer_flat = tf.reshape(layer, new[] { -1, num_features });
 
                       return layer_flat;
                   });
}
 
/// <summary>
/// Create a weight variable with appropriate initialization
/// </summary>
/// <param name="name"></param>
/// <param name="shape"></param>
/// <returns></returns>
private RefVariable weight_variable(string name, int[] shape)
{
    var initer = tf.truncated_normal_initializer(stddev: 0.01f);
    return tf.get_variable(name,
                           dtype: tf.float32,
                           shape: shape,
                           initializer: initer);
}
 
/// <summary>
/// Create a bias variable with appropriate initialization
/// </summary>
/// <param name="name"></param>
/// <param name="shape"></param>
/// <returns></returns>
private RefVariable bias_variable(string name, int[] shape)
{
    var initial = tf.constant(0f, shape: shape, dtype: tf.float32);
    return tf.get_variable(name,
                           dtype: tf.float32,
                           initializer: initial);
}
 
/// <summary>
/// Create a fully-connected layer
/// </summary>
/// <param name="x">input from previous layer</param>
/// <param name="num_units">number of hidden units in the fully-connected layer</param>
/// <param name="name">layer name</param>
/// <param name="use_relu">boolean to add ReLU non-linearity (or not)</param>
/// <returns>The output array</returns>
private Tensor fc_layer(Tensor x, int num_units, string name, bool use_relu = true)
{
    return tf_with(tf.variable_scope(name), delegate
                   {
                       var in_dim = x.shape[1];
 
                       var W = weight_variable("W_" + name, shape: new[] { in_dim, num_units });
                       var b = bias_variable("b_" + name, new[] { num_units });
 
                       var layer = tf.matmul(x, W) + b;
                       if (use_relu)
                           layer = tf.nn.relu(layer);
 
                       return layer;
                   });
}
#endregion           

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模型訓練和模型儲存

· Batch資料集的讀取,采用了 SharpCV 的cv2.imread,可以直接讀取本地圖像檔案至NDArray,實作CV和Numpy的無縫對接;

· 使用.NET的異步線程安全隊列BlockingCollection,實作TensorFlow原生的隊列管理器FIFOQueue;

    • 在訓練模型的時候,我們需要将樣本從硬碟讀取到記憶體之後,才能進行訓練。我們在會話中運作多個線程,并加入隊列管理器進行線程間的檔案入隊出隊操作,并限制隊列容量,主線程可以利用隊列中的資料進行訓練,另一個線程進行本地檔案的IO讀取,這樣可以實作資料的讀取和模型的訓練是異步的,降低訓練時間。

· 模型的儲存,可以選擇每輪訓練都儲存,或最佳訓練模型儲存

·       #region Train
·       public void Train(Session sess)
·       {
·           // Number of training iterations in each epoch
·           var num_tr_iter = (ArrayLabel_Train.Length) / batch_size;
·        
·           var init = tf.global_variables_initializer();
·           sess.run(init);
·        
·           var saver = tf.train.Saver(tf.global_variables(), max_to_keep: 10);
·        
·           path_model = Name + "\\MODEL";
·           Directory.CreateDirectory(path_model);
·        
·           float loss_val = 100.0f;
·           float accuracy_val = 0f;
·        
·           var sw = new Stopwatch();
·           sw.Start();
·           foreach (var epoch in range(epochs))
·           {
·               print($"Training epoch: {epoch + 1}");
·               // Randomly shuffle the training data at the beginning of each epoch 
·               (ArrayFileName_Train, ArrayLabel_Train) = ShuffleArray(ArrayLabel_Train.Length, ArrayFileName_Train, ArrayLabel_Train);
·               y_train = np.eye(Dict_Label.Count)[new NDArray(ArrayLabel_Train)];
·        
·               //decay learning rate
·               if (learning_rate_step != 0)
·               {
·                   if ((epoch != 0) && (epoch % learning_rate_step == 0))
·                   {
·                       learning_rate_base = learning_rate_base * learning_rate_decay;
·                       if (learning_rate_base <= learning_rate_min) { learning_rate_base = learning_rate_min; }
·                       sess.run(tf.assign(learning_rate, learning_rate_base));
·                   }
·               }
·        
·                //Load local images asynchronously,use queue,improve train efficiency
·               BlockingCollection<(NDArray c_x, NDArray c_y, int iter)> BlockC = new BlockingCollection<(NDArray C1, NDArray C2, int iter)>(TrainQueueCapa);
·               Task.Run(() =>
·                        {
·                            foreach (var iteration in range(num_tr_iter))
·                            {
·                                var start = iteration * batch_size;
·                                var end = (iteration + 1) * batch_size;
·                                (NDArray x_batch, NDArray y_batch) = GetNextBatch(sess, ArrayFileName_Train, y_train, start, end);
·                                BlockC.Add((x_batch, y_batch, iteration));
·                            }
·                            BlockC.CompleteAdding();
·                        });
·        
·               foreach (var item in BlockC.GetConsumingEnumerable())
·               {
·                   sess.run(optimizer, (x, item.c_x), (y, item.c_y));
·        
·                   if (item.iter % display_freq == 0)
·                   {
·                       // Calculate and display the batch loss and accuracy
·                       var result = sess.run(new[] { loss, accuracy }, new FeedItem(x, item.c_x), new FeedItem(y, item.c_y));
·                       loss_val = result[0];
·                       accuracy_val = result[1];
·                       print("CNN:" + ($"iter {item.iter.ToString("000")}: Loss={loss_val.ToString("0.0000")}, Training Accuracy={accuracy_val.ToString("P")} {sw.ElapsedMilliseconds}ms"));
·                       sw.Restart();
·                   }
·               }             
·        
·               // Run validation after every epoch
·               (loss_val, accuracy_val) = sess.run((loss, accuracy), (x, x_valid), (y, y_valid));
·               print("CNN:" + "---------------------------------------------------------");
·               print("CNN:" + $"gloabl steps: {sess.run(gloabl_steps) },learning rate: {sess.run(learning_rate)}, validation loss: {loss_val.ToString("0.0000")}, validation accuracy: {accuracy_val.ToString("P")}");
·               print("CNN:" + "---------------------------------------------------------");
·        
·               if (SaverBest)
·               {
·                   if (accuracy_val > max_accuracy)
·                   {
·                       max_accuracy = accuracy_val;
·                       saver.save(sess, path_model + "\\CNN_Best");
·                       print("CKPT Model is save.");
·                   }
·               }
·               else
·               {
·                   saver.save(sess, path_model + string.Format("\\CNN_Epoch_{0}_Loss_{1}_Acc_{2}", epoch, loss_val, accuracy_val));
·                   print("CKPT Model is save.");
·               }
·           }
·           Write_Dictionary(path_model + "\\dic.txt", Dict_Label);
·       }
·       private void Write_Dictionary(string path, Dictionary<Int64, string> mydic)
·       {
·           FileStream fs = new FileStream(path, FileMode.Create);
·           StreamWriter sw = new StreamWriter(fs);
·           foreach (var d in mydic) { sw.Write(d.Key + "," + d.Value + "\r\n"); }
·           sw.Flush();
·           sw.Close();
·           fs.Close();
·           print("Write_Dictionary");
·       }
·       private (NDArray, NDArray) Randomize(NDArray x, NDArray y)
·       {
·           var perm = np.random.permutation(y.shape[0]);
·           np.random.shuffle(perm);
·           return (x[perm], y[perm]);
·       }
·       private (NDArray, NDArray) GetNextBatch(NDArray x, NDArray y, int start, int end)
·       {
·           var slice = new Slice(start, end);
·           var x_batch = x[slice];
·           var y_batch = y[slice];
·           return (x_batch, y_batch);
·       }
·       private unsafe (NDArray, NDArray) GetNextBatch(Session sess, string[] x, NDArray y, int start, int end)
·       {
·           NDArray x_batch = np.zeros(end - start, img_h, img_w, n_channels);
·           int n = 0;
·           for (int i = start; i < end; i++)
·           {
·             NDArray img4 = cv2.imread(x[i], IMREAD_COLOR.IMREAD_GRAYSCALE);
·               x_batch[n] = sess.run(normalized, (decodeJpeg, img4));
·               n++;
·           }
·           var slice = new Slice(start, end);
·           var y_batch = y[slice];
·           return (x_batch, y_batch);
·       }
·       #endregion           

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測試集預測

· 訓練完成的模型對test資料集進行預測,并統計準确率

· 計算圖中增加了一個提取預測結果Top-1的機率的節點,最後測試集預測的時候可以把詳細的預測資料進行輸出,友善實際工程中進行調試和優化。

·       public void Test(Session sess)
·       {
·           (loss_test, accuracy_test) = sess.run((loss, accuracy), (x, x_test), (y, y_test));
·           print("CNN:" + "---------------------------------------------------------");
·           print("CNN:" + $"Test loss: {loss_test.ToString("0.0000")}, test accuracy: {accuracy_test.ToString("P")}");
·           print("CNN:" + "---------------------------------------------------------");
·        
·           (Test_Cls, Test_Data) = sess.run((cls_prediction, prob), (x, x_test));
·        
·       }
·       private void TestDataOutput()
·       {
·           for (int i = 0; i < ArrayLabel_Test.Length; i++)
·           {
·               Int64 real = ArrayLabel_Test[i];
·               int predict = (int)(Test_Cls[i]);
·               var probability = Test_Data[i, predict];
·               string result = (real == predict) ? "OK" : "NG";
·               string fileName = ArrayFileName_Test[i];
·               string real_str = Dict_Label[real];
·               string predict_str = Dict_Label[predict];
·               print((i + 1).ToString() + "|" + "result:" + result + "|" + "real_str:" + real_str + "|"
·                     + "predict_str:" + predict_str + "|" + "probability:" + probability.GetSingle().ToString() + "|"
·                     + "fileName:" + fileName);
·           }
·       }
           

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總結

本文主要是 .NET下的TensorFlow在實際工業現場視覺檢測項目中的應用,使用SciSharp的TensorFlow.NET建構了簡單的CNN圖像分類模型,該模型包含輸入層、卷積與池化層、扁平化層、全連接配接層和輸出層,這些層都是CNN分類模型的必要的層,針對工業現場的實際圖像進行了分類,分類準确性較高。

完整代碼可以直接用于大家自己的資料集進行訓練,已經在工業現場經過大量測試,可以在GPU或CPU環境下運作,隻需要更換tensorflow.dll檔案即可實作訓練環境的切換。

同時,訓練完成的模型檔案,可以使用 “CKPT+Meta” 或 當機成“PB” 2種方式,進行現場的部署,模型部署和現場應用推理可以全部在.NET平台下進行,實作工業現場程式的無縫對接。擺脫了以往Python下 需要通過Flask搭建伺服器進行資料通訊互動 的方式,現場部署應用時無需配置Python和TensorFlow的環境【無需對工業現場的原有PC更新安裝一大堆環境】,整個過程全部使用傳統的.NET的DLL引用的方式。