基于Android studio3.6的JNI教程之ncnn之分类之squeezenet

 

代码链接：

https://github.com/watersink/SqueezeClassify-as

本代码可以在模拟器下进行跑。

 

环境：

Android studio 3.6

Sdk：android10 api 29

Ndk：r15c

Ncnn：20200226

 

Android下开发：

(1)增加模型文件，（src/main/assets）

在src/main/cpp下面增加模型的.id.h文件，

(2)增加ncnn库文件（src/main/jniLibs）

增加ncnn的头文件，（src/main/cpp/include）

(3)修改布局文件，src/main/res/layout

<?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/buttonImage"
        android:layout_weight="1"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:text="选图"/>
    <Button
        android:id="@+id/buttonDetect"
        android:layout_weight="1"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:text="检测"/>
</LinearLayout>

<TextView
    android:id="@+id/infoResult"
    android:layout_width="match_parent"
    android:layout_height="100dp"
    android:layout_above="@id/btn_ll"
    android:hint="预测结果会在这里显示"
    android:textSize="16sp" />

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

(4)修改java层代码src/main/java

SqueezeNcnn层代码，

public class SqueezeNcnn
{
    public native boolean Init(byte[] param, byte[] bin, byte[] words);
    public native String Detect(Bitmap bitmap);
    static {
        System.loadLibrary("squeeze");
    }
}

MainActivity层代码，

public class MainActivity extends AppCompatActivity {

    private static final int SELECT_IMAGE = 1;
    private TextView infoResult;
    private ImageView imageView;
    private Bitmap yourSelectedImage = null;

    private SqueezeNcnn squeezencnn = new SqueezeNcnn();

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);


        try
        {
            initSqueezeNcnn();
        }
        catch (IOException e)
        {
            Log.e("MainActivity", "initSqueezeNcnn error");
        }

        infoResult = (TextView) findViewById(R.id.infoResult);
        imageView = (ImageView) findViewById(R.id.imageView);

        Button buttonImage = (Button) findViewById(R.id.buttonImage);
        buttonImage.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 buttonDetect = (Button) findViewById(R.id.buttonDetect);
        buttonDetect.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View arg0) {
                if (yourSelectedImage == null)
                    return;

                String result = squeezencnn.Detect(yourSelectedImage);

                if (result == null)
                {
                    infoResult.setText("detect failed");
                }
                else
                {
                    infoResult.setText(result);
                }
            }
        });


    }


    private void initSqueezeNcnn() throws IOException
    {
        byte[] param = null;
        byte[] bin = null;
        byte[] words = null;

        {
            InputStream assetsInputStream = getAssets().open("squeezenet_v1.1.param.bin");
            int available = assetsInputStream.available();
            param = new byte[available];
            int byteCode = assetsInputStream.read(param);
            assetsInputStream.close();
        }
        {
            InputStream assetsInputStream = getAssets().open("squeezenet_v1.1.bin");
            int available = assetsInputStream.available();
            bin = new byte[available];
            int byteCode = assetsInputStream.read(bin);
            assetsInputStream.close();
        }
        {
            InputStream assetsInputStream = getAssets().open("synset_words.txt");
            int available = assetsInputStream.available();
            words = new byte[available];
            int byteCode = assetsInputStream.read(words);
            assetsInputStream.close();
        }

        squeezencnn.Init(param, bin, words);
    }

    @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 227x227
                    yourSelectedImage = Bitmap.createScaledBitmap(rgba, 227, 227, false);

                    imageView.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 = 400;

        // 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);
    }


}

(5)修改cpp层代码，squeezencnn_jni.cpp

static std::vector<std::string> split_string(const std::string& str, const std::string& delimiter)
{
    std::vector<std::string> strings;

    std::string::size_type pos = 0;
    std::string::size_type prev = 0;
    while ((pos = str.find(delimiter, prev)) != std::string::npos)
    {
        strings.push_back(str.substr(prev, pos - prev));
        prev = pos + 1;
    }

    // To get the last substring (or only, if delimiter is not found)
    strings.push_back(str.substr(prev));

    return strings;
}


extern "C"
JNIEXPORT jboolean JNICALL
Java_com_example_squeezeclassify_SqueezeNcnn_Init(JNIEnv *env, jobject thiz, jbyteArray param,
                                                  jbyteArray bin, jbyteArray words) {
    // TODO: implement Init()
    {
        int len = env->GetArrayLength(param);
        squeezenet_param.resize(len);
        env->GetByteArrayRegion(param, 0, len, (jbyte*)squeezenet_param.data());
        int ret = squeezenet.load_param(squeezenet_param.data());
        __android_log_print(ANDROID_LOG_DEBUG, "SqueezeNcnn", "load_param %d %d", ret, len);
    }

    // init bin
    {
        int len = env->GetArrayLength(bin);
        squeezenet_bin.resize(len);
        env->GetByteArrayRegion(bin, 0, len, (jbyte*)squeezenet_bin.data());
        int ret = squeezenet.load_model(squeezenet_bin.data());
        __android_log_print(ANDROID_LOG_DEBUG, "SqueezeNcnn", "load_model %d %d", ret, len);
    }

    // init words
    {
        int len = env->GetArrayLength(words);
        std::string words_buffer;
        words_buffer.resize(len);
        env->GetByteArrayRegion(words, 0, len, (jbyte*)words_buffer.data());
        squeezenet_words = split_string(words_buffer, "\n");
    }

    return JNI_TRUE;

}


extern "C"
JNIEXPORT jstring JNICALL
Java_com_example_squeezeclassify_SqueezeNcnn_Detect(JNIEnv *env, jobject thiz, jobject bitmap) {
    // TODO: implement Detect()
    bench_start();

    // ncnn from bitmap
    ncnn::Mat in;
    {
        AndroidBitmapInfo info;
        AndroidBitmap_getInfo(env, bitmap, &info);
        int width = info.width;
        int height = info.height;
        if (width != 227 || height != 227)
            return NULL;
        if (info.format != ANDROID_BITMAP_FORMAT_RGBA_8888)
            return NULL;

        void* indata;
        AndroidBitmap_lockPixels(env, bitmap, &indata);
        in = ncnn::Mat::from_pixels((const unsigned char*)indata, ncnn::Mat::PIXEL_RGBA2BGR, width, height);
        AndroidBitmap_unlockPixels(env, bitmap);
    }

    // squeezenet
    // return top class
    int top_class = 0;
    float max_score = 0.f;
    {
        const float mean_vals[3] = {104.f, 117.f, 123.f};
        in.substract_mean_normalize(mean_vals, 0);

        ncnn::Extractor ex = squeezenet.create_extractor();
        ex.set_light_mode(true);
        ex.set_num_threads(4);

        ex.input(squeezenet_v1_1_param_id::BLOB_data, in);
        ncnn::Mat out;
        ex.extract(squeezenet_v1_1_param_id::BLOB_prob, out);

        for (int j=0; j<out.w; j++)
        {
            if (out[j]>max_score){
                max_score =out[j];
                top_class = j;
            }
        }

    }

    const std::string& word = squeezenet_words[top_class];
    char tmp[32];
    sprintf(tmp, "%.3f", max_score);
    std::string result_str = std::string(word.c_str() + 10) + " = " + tmp;

    // +10 to skip leading n03179701
    jstring result = env->NewStringUTF(result_str.c_str());
    bench_end("detect");
    return result;

}

 

(6)修改CMakeLists.txt

cmake_minimum_required(VERSION 3.4.1)

#include头文件目录
include_directories(include)

#添加ncnn库
#source directory源文件目录
file(GLOB squeeze_SRC *.h
        *.cpp)
set(squeeze_COMPILE_CODE ${squeeze_SRC})

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.
        squeeze ## 为生成.so的文字最好直接和.c名字一样,需要更改
        # Sets the library as a shared library.
        SHARED
        # Provides a relative path to your source file(s).
        ${squeeze_COMPILE_CODE})##cpp文件的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.
                       squeeze
                       libncnn
                       android
                       jnigraphics
                       # Links the target library to the log library
                       # included in the NDK.
                       ${log-lib} )

 

(7)修改app/build.gradle

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"
        }

 

整体目录结构：

 

测试结果：