程式碼連結：

https://github.com/watersink/enet-as-linux

本程式碼可以在模擬器下進行跑。

環境：

Android studio 3.6

Sdk：android10 api 29

Ndk：r15c

Ncnn：20200226

Opencv：Opencv3.4.1 android sdk

Linux下的程式碼測試：

mkdir build
cd build
cmake ..
make
./enet

執行效果，

Android開始：

(1)新建工程，

New->New Project->選擇Native c++ ->工程名enet->c++11

(2)app/src/cpp下面增加opencv和ncnn的標頭檔案，include

(3)app/src/main下面增加ncnn 和opencv的靜態庫檔案和動態庫檔案，

(4)app/src/main下面增加模型檔案assets

(5)修改佈局檔案，app/src/main/res/layout/ activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
 xmlns:app="http://schemas.android.com/apk/res-auto"
 xmlns:tools="http://schemas.android.com/tools"
 android:layout_width="match_parent"
 android:layout_height="match_parent"
 tools:context=".MainActivity">
 <LinearLayout
  android:id="@+id/btn_ll"
  android:layout_alignParentBottom="true"
  android:layout_width="match_parent"
  android:layout_height="wrap_content"
  android:orientation="horizontal">
  <Button
   android:id="@+id/use_photo"
   android:layout_weight="1"
   android:layout_width="0dp"
   android:layout_height="wrap_content"
   android:text="選圖"/>
  <Button
   android:id="@+id/detect_photo"
   android:layout_weight="1"
   android:layout_width="0dp"
   android:layout_height="wrap_content"
   android:text="分割"/>
 </LinearLayout>

 <ImageView
  android:id="@+id/show_image"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  android:layout_above="@id/btn_ll"
  android:layout_alignParentTop="true"
  android:layout_marginTop="1dp"
  android:layout_marginBottom="-1dp" />
</RelativeLayout>

(6) app/src/main/java/com/example/enet增加ENET類，

public class ENET {
 public native boolean Init(byte[] param,byte[] bin);
 public native float[] Process(Bitmap bitmap);
 // Used to load the 'native-lib' library on application startup.
 
 static {
  System.loadLibrary("ENET");
 }
}

(7) app/src/main/cpp/enet-jni.cpp實現其jni方法，

extern "C"
JNIEXPORT jboolean JNICALL
Java_com_example_enet_ENET_Init(JNIEnv *env,jobject thiz,jbyteArray param,jbyteArray bin) {
 // TODO: implement Init()
 ncnn::Mat ncnn_param;
 ncnn::Mat ncnn_bin;
 // init param
 {
  int len = env->GetArrayLength(param);
  ncnn_param.create(len,(size_t) 1u);
  env->GetByteArrayRegion(param,len,(jbyte *) ncnn_param);
 }
 // init bin
 {
  int len = env->GetArrayLength(bin);
  ncnn_bin.create(len,(size_t) 1u);
  env->GetByteArrayRegion(bin,(jbyte *) ncnn_bin);
 }
 ncnn_net = new ENET(ncnn_param,ncnn_bin);
 return JNI_TRUE;
}
extern "C"
JNIEXPORT jfloatArray JNICALL
Java_com_example_enet_ENET_Process(JNIEnv *env,jobject bitmap) {
 // TODO: implement Process()
 // ncnn from bitmap
 ncnn::Mat in;
 {
  AndroidBitmapInfo info;
  AndroidBitmap_getInfo(env,bitmap,&info);
  int width = info.width;
  int height = info.height;
  if (info.format != ANDROID_BITMAP_FORMAT_RGBA_8888)
   return NULL;
  void* indata;
  AndroidBitmap_lockPixels(env,&indata);
  // 把畫素轉換成data，並指定通道順序
  // 因為影象預處理每個網路層輸入的資料格式不一樣一般為300*300 128*128等等所以這類需要一個resize的操作可以在cpp中寫，也可以是java讀入圖片時有個resize操作
  //in = ncnn::Mat::from_pixels_resize((const unsigned char*)indata,ncnn::Mat::PIXEL_RGBA2RGB,width,height,300,300);
  in = ncnn::Mat::from_pixels(static_cast<const unsigned char *>(indata),ncnn::Mat::PIXEL_RGBA2BGR,height);
  // 下面一行為debug程式碼
  __android_log_print(ANDROID_LOG_DEBUG,"ENetJniIn","enet_process_has_input1,in.w: %d; in.h: %d in.c:%d ",in.w,in.h,in.c);
  //AndroidBitmap_unlockPixels(env,bitmap);
 }
 {
  ncnn::Mat out = ncnn_net->process(in);
  __android_log_print(ANDROID_LOG_DEBUG,"enet_process_has_output,out.w,out.h,out.c);
  int output_wsize = out.w;
  int output_hsize = out.h;
  //輸出整理
  float *output[output_wsize * output_hsize]; // float型別
  for(int i = 0; i< out.h; i++) {
   for (int j = 0; j < out.w; j++) {
    output[i*output_wsize + j] = &out.row(
      i)[j];
   }
  }
  //建立float陣列 長度為 output_wsize * output_hsize,如果只是ouput_size相當於只有一行的out的資料那就是一個object檢測資料
  jfloatArray jOutputData = env->NewFloatArray(output_wsize * output_hsize);
  if (jOutputData == nullptr) return nullptr;
  env->SetFloatArrayRegion(jOutputData,output_wsize * output_hsize,reinterpret_cast<const jfloat *>(*output));
  return jOutputData;
 }
}

(8) app/src/main/java/com/example/enet中MainActivity做具體的呼叫實現，

public class MainActivity extends AppCompatActivity {
 private ENET enet = new ENET(); //java介面例項化　下面直接利用java函式呼叫NDK c++函式
 private Bitmap yourSelectedImage = null;
 private static final int SELECT_IMAGE = 1;
 private static final String TAG = MainActivity.class.getName();
 private ImageView show_image;
 private boolean load_result = false;
 private int[] ddims = {1,3,512,288}; //這裡的維度的值要和train model的input 一一對應
 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_main);
  try
  {
   initENet();//初始化模型
   Log.e("MainActivity","initENet ok");
  } catch (IOException e) {
   Log.e("MainActivity","initENet error");
  }
  init_view();//檢測+view畫圖
 }
 // initialize view
 private void init_view() {
  show_image = (ImageView) findViewById(R.id.show_image);
  Button use_photo = (Button) findViewById(R.id.use_photo);
  use_photo.setOnClickListener(new View.OnClickListener() {
   @Override
   public void onClick(View arg0) {
    Intent i = new Intent(Intent.ACTION_PICK);
    i.setType("image/*");
    startActivityForResult(i,SELECT_IMAGE);
   }
  });
  Button detect_photo = (Button) findViewById(R.id.detect_photo);
  detect_photo.setOnClickListener(new View.OnClickListener() {
   @Override
   public void onClick(View arg0) {
    if (yourSelectedImage == null)
     return;
    predict_image(yourSelectedImage);
   }
  });
 }
 private void initENet() throws IOException {
  byte[] param = null;
  byte[] bin = null;
  {
   //用io流讀取二進位制檔案，最後存入到byte[]陣列中
   InputStream assetsInputStream = getAssets().open("enet_512288.param.bin");// param： 網路結構檔案
   int available = assetsInputStream.available();
   param = new byte[available];
   int byteCode = assetsInputStream.read(param);
   assetsInputStream.close();
  }
  {
   //用io流讀取二進位制檔案，最後存入到byte上，轉換為int型
   InputStream assetsInputStream = getAssets().open("enet_512288.bin");//bin： model檔案
   int available = assetsInputStream.available();
   bin = new byte[available];
   int byteCode = assetsInputStream.read(bin);
   assetsInputStream.close();
  }
  load_result = enet.Init(param,bin);// 再將檔案傳入java的NDK介面(c++ 程式碼中的init介面 )
  Log.d("load model","ENet_load_model_result:" + load_result);
 }
 @Override
 protected void onActivityResult(int requestCode,int resultCode,Intent data)
 {
  super.onActivityResult(requestCode,resultCode,data);
  if (resultCode == RESULT_OK && null != data) {
   Uri selectedImage = data.getData();
   try
   {
    if (requestCode == SELECT_IMAGE) {
     Bitmap bitmap = decodeUri(selectedImage);
     Bitmap rgba = bitmap.copy(Bitmap.Config.ARGB_8888,true);
     // resize to 512x288
     yourSelectedImage = Bitmap.createScaledBitmap(rgba,ddims[2],ddims[3],false);
     show_image.setImageBitmap(yourSelectedImage);
    }
   }
   catch (FileNotFoundException e)
   {
    Log.e("MainActivity","FileNotFoundException");
    return;
   }
  }
 }
 private Bitmap decodeUri(Uri selectedImage) throws FileNotFoundException
 {
  // Decode image size
  BitmapFactory.Options o = new BitmapFactory.Options();
  o.inJustDecodeBounds = true;
  BitmapFactory.decodeStream(getContentResolver().openInputStream(selectedImage),null,o);
  // The new size we want to scale to
  final int REQUIRED_SIZE = 600;
  // Find the correct scale value. It should be the power of 2.
  int width_tmp = o.outWidth,height_tmp = o.outHeight;
  int scale = 1;
  while (true) {
   if (width_tmp / 2 < REQUIRED_SIZE
     || height_tmp / 2 < REQUIRED_SIZE) {
    break;
   }
   width_tmp /= 2;
   height_tmp /= 2;
   scale *= 2;
  }
  // Decode with inSampleSize
  BitmapFactory.Options o2 = new BitmapFactory.Options();
  o2.inSampleSize = scale;
  return BitmapFactory.decodeStream(getContentResolver().openInputStream(selectedImage),o2);
 }
 // predict image
 private void predict_image(Bitmap bmp) {
  // picture to float array
  Bitmap rgba = bmp.copy(Bitmap.Config.ARGB_8888,true);
  // resize
  Bitmap input_bmp = Bitmap.createScaledBitmap(rgba,false);
  try {
   // Data format conversion takes too long
   // Log.d("inputData",Arrays.toString(inputData));
   long start = System.currentTimeMillis();
   // get predict result
   float[] result = enet.Process(input_bmp);
   // time end
   long end = System.currentTimeMillis();
   Log.d(TAG,"origin predict result:" + Arrays.toString(result));
   long time = end - start;
   Log.d("result length","length of result: " + String.valueOf(result.length));
   // 畫布配置
   Canvas canvas = new Canvas(input_bmp);
   //影象上畫矩形
   Paint paint = new Paint();
   //continue to draw rect
   Log.d(TAG,"result :" + result.length);
   Log.d(TAG,"result :" + Arrays.toString(result));
   for(int num = 0; num < result.length; num++){
    // 畫框
    int row =num%ddims[2];
    int col = num/ddims[2];
    if (result[num]==1){
     paint.setColor(Color.RED);
     paint.setStyle(Paint.Style.STROKE);//不填充
     canvas.drawCircle(row,col,1,paint);
    }
    if (result[num]==2){
     paint.setColor(Color.BLUE);
     paint.setStyle(Paint.Style.STROKE);//不填充
     canvas.drawCircle(row,paint);
    }
    if (result[num]==3){
     paint.setColor(Color.GREEN);
     paint.setStyle(Paint.Style.STROKE);//不填充
     canvas.drawCircle(row,paint);
    }
   }
   show_image.setImageBitmap(input_bmp);
  } catch (Exception e) {
   e.printStackTrace();
  }
 }
}

(9) app/src/main/cpp下面修改CMakeLists

cmake_minimum_required(VERSION 3.4.1)
include_directories(include)
file(GLOB ENET_SRC *.h
  *.cpp)
set(ENET_COMPILE_CODE ${ENET_SRC})
add_library(libopencv_java3 SHARED IMPORTED)
set_target_properties(libopencv_java3 PROPERTIES IMPORTED_LOCATION
  ${CMAKE_SOURCE_DIR}/../jniLibs/${ANDROID_ABI}/libopencv_java3.so)
 
add_library(libncnn STATIC IMPORTED )
set_target_properties(libncnn
  PROPERTIES IMPORTED_LOCATION
  ${CMAKE_SOURCE_DIR}/../jniLibs/${ANDROID_ABI}/libncnn.a)
add_library( # Sets the name of the library.
  ENET ## 為生成.so的文字最好直接和.c名字一樣,需要更改
  # Sets the library as a shared library.
  SHARED
  # Provides a relative path to your source file(s).
  ${ENET_COMPILE_CODE})##cpp檔案的name
find_library( # Sets the name of the path variable.
    log-lib
 
    # Specifies the name of the NDK library that
    # you want CMake to locate.
    log )
target_link_libraries( # Specifies the target library.
      ENET
      libncnn
      libopencv_java3
      jnigraphics
      android
      # Links the target library to the log library
      # included in the NDK.
      ${log-lib} )

(10) app/src/下面修改build.gradle，增加下面的設定，

externalNativeBuild {
   cmake {
    arguments "-DANDROID_TOOLCHAIN=clang"
    cFlags "-fopenmp -O2 -fvisibility=hidden -fomit-frame-pointer -fstrict-aliasing -ffunction-sections -fdata-sections -ffast-math "
    cppFlags "-fopenmp -O2 -fvisibility=hidden -fvisibility-inlines-hidden -fomit-frame-pointer -fstrict-aliasing -ffunction-sections -fdata-sections -ffast-math "
    arguments "-DANDROID_STL=c++_shared","-DANDROID_CPP_FEATURES=rtti exceptions"
    cppFlags ""
    cppFlags "-std=c++11"
    cppFlags "-frtti"
    cppFlags "-fexceptions"
   }
  }
  ndk {
   abiFilters 'armeabi-v7a'//,'arm64-v8a' //,'x86','x86_64','armeabi'
   stl "gnustl_static"
  }

整體目錄結構：

最終效果：

總結

到此這篇關於基於Android studio3.6的JNI教程之ncnn之語義分割ENet的文章就介紹到這了,更多相關android studio 語義分割enet內容請搜尋我們以前的文章或繼續瀏覽下面的相關文章希望大家以後多多支援我們！