代碼鏈接：

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

本代碼可以在模擬器下進(jìn)行跑。

環(huán)境：

Android studio 3.6

Sdk：android10 api 29

Ndk：r15c

Ncnn：20200226

Opencv：Opencv3.4.1 android sdk

Linux下的代碼測試：

mkdir buildcd buildcmake ..make./enet

運行效果，

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的頭文件，include

(3)app/src/main下面增加ncnn 和opencv的靜態(tài)庫文件和動態(tài)庫文件，

(4)app/src/main下面增加模型文件assets

(5)修改布局文件，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: android:layout_alignParentBottom='true' android:layout_width='match_parent' android:layout_height='wrap_content' android:orientation='horizontal'> <Button android: android:layout_weight='1' android:layout_width='0dp' android:layout_height='wrap_content' android:text='選圖'/> <Button android: android:layout_weight='1' android:layout_width='0dp' android:layout_height='wrap_content' android:text='分割'/> </LinearLayout> <ImageView android: 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(xiàn)其jni方法，

extern 'C'JNIEXPORT jboolean JNICALLJava_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, 0, len, (jbyte *) ncnn_param); } // init bin { int len = env->GetArrayLength(bin); ncnn_bin.create(len, (size_t) 1u); env->GetByteArrayRegion(bin, 0, len, (jbyte *) ncnn_bin); } ncnn_net = new ENET(ncnn_param,ncnn_bin); return JNI_TRUE;}extern 'C'JNIEXPORT jfloatArray JNICALLJava_com_example_enet_ENET_Process(JNIEnv *env, jobject thiz, 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, bitmap, &indata); // 把像素轉(zhuǎn)換成data，并指定通道順序 // 因為圖像預(yù)處理每個網(wǎng)絡(luò)層輸入的數(shù)據(jù)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, width, height); // 下面一行為debug代碼 __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, 'ENetJniIn', 'enet_process_has_output, in.w: %d; in.h: %d in.c:%d ', 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類型 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數(shù)組 長度為 output_wsize * output_hsize,如果只是ouput_size相當(dāng)于只有一行的out的數(shù)據(jù)那就是一個object檢測數(shù)據(jù) jfloatArray jOutputData = env->NewFloatArray(output_wsize * output_hsize); if (jOutputData == nullptr) return nullptr; env->SetFloatArrayRegion(jOutputData, 0, output_wsize * output_hsize,reinterpret_cast<const jfloat *>(*output)); return jOutputData; }}

(8) app/src/main/java/com/example/enet中MainActivity做具體的調(diào)用實現(xiàn)，

public class MainActivity extends AppCompatActivity { private ENET enet = new ENET(); //java接口實例化　下面直接利用java函數(shù)調(diào)用NDK c++函數(shù) 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}; //這里的維度的值要和train model的input 一一對應(yīng) @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(jìn)制文件，最后存入到byte[]數(shù)組中 InputStream assetsInputStream = getAssets().open('enet_512288.param.bin');// param： 網(wǎng)絡(luò)結(jié)構(gòu)文件 int available = assetsInputStream.available(); param = new byte[available]; int byteCode = assetsInputStream.read(param); assetsInputStream.close(); } { //用io流讀取二進(jìn)制文件，最后存入到byte上，轉(zhuǎn)換為int型 InputStream assetsInputStream = getAssets().open('enet_512288.bin');//bin： model文件 int available = assetsInputStream.available(); bin = new byte[available]; int byteCode = assetsInputStream.read(bin); assetsInputStream.close(); } load_result = enet.Init(param, bin);// 再將文件傳入java的NDK接口(c++ 代碼中的init接口 ) 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), null, 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, ddims[2], ddims[3], 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); //圖像上畫矩形 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, col, 1, paint); } if (result[num]==3){ paint.setColor(Color.GREEN); paint.setStyle(Paint.Style.STROKE);//不填充 canvas.drawCircle(row, col, 1, 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文件的namefind_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(shè)置，

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(jié)構(gòu)：

最終效果：

總結(jié)

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