android cpp

MainActivity

package com.example.mothimport android.content.Intentimport android.content.res.AssetManagerimport android.graphics.Bitmapimport android.os.Bundleimport android.util.Logimport android.view.Menuimport android.view.MenuItemimport android.widget.Buttonimport android.widget.TextViewimport android.widget.Toastimport com.google.android.material.snackbar.Snackbarimport com.google.android.material.navigation.NavigationViewimport androidx.navigation.findNavControllerimport androidx.navigation.ui.AppBarConfigurationimport androidx.navigation.ui.navigateUpimport androidx.navigation.ui.setupActionBarWithNavControllerimport androidx.navigation.ui.setupWithNavControllerimport androidx.drawerlayout.widget.DrawerLayoutimport androidx.appcompat.app.AppCompatActivityimport com.example.moth.databinding.ActivityMainBindingimport java.io.ByteArrayOutputStreamimport okhttp3.MediaTypeimport okhttp3.MultipartBodyimport retrofit2.Callimport retrofit2.Callbackimport retrofit2.Responseimport com.example.moth.httpInterface.RecognizeClient.recognizeServiceimport com.example.moth.httpInterface.PredictResponseimport com.example.moth.httpInterface.PredictResultclass MainActivity : AppCompatActivity() { private lateinit var appBarConfiguration: AppBarConfiguration private lateinit var binding: ActivityMainBinding private var selectedBitMap: Bitmap? = null private lateinit var recognizeResultTextView: TextView private lateinit var assetManager: AssetManager companion object { // 加载本地库 init { System.loadLibrary(\"native-lib\") } } // 声明静态native方法 private external fun staticProcessImage(bitmap: Bitmap): String private val insectMapping = mapOf( \"0\" to \"稻纵卷叶螟\", \"1\" to \"亚洲稻螟虫\", \"2\" to \"白蛾\", \"3\" to \"鬼脸天蛾\", \"4\" to \"玉米螟\", \"5\" to \"夜盗蛾\", \"6\" to \"桃蛀螟\", \"7\" to \"甘蓝夜蛾\", \"8\" to \"草地贪夜蛾\", \"9\" to \"斜带葡萄天蛾\", \"10\" to \"棉斜纹夜蛾\", \"11\" to \"枯叶夜蛾\", \"12\" to \"横线尾夜蛾\" ) override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) // 检查token val sharedPreferences = getSharedPreferences(\"AppPreferences\", MODE_PRIVATE) val token = sharedPreferences.getString(\"token\", null) if(token == null){ val intent = Intent(this, LoginActivity::class.java) startActivity(intent) finish() return } assetManager = assets binding = ActivityMainBinding.inflate(layoutInflater) setContentView(binding.root) setSupportActionBar(binding.appBarMain.toolbar) binding.appBarMain.fab.setOnClickListener { view -> Snackbar.make(view, \"Replace with your own action\", Snackbar.LENGTH_LONG) .setAction(\"Action\", null) .setAnchorView(R.id.fab).show() } val drawerLayout: DrawerLayout = binding.drawerLayout val navView: NavigationView = binding.navView val navController = findNavController(R.id.nav_host_fragment_content_main) // Passing each menu ID as a set of Ids because each // menu should be considered as top level destinations. appBarConfiguration = AppBarConfiguration( setOf( R.id.nav_home, R.id.nav_gallery, R.id.nav_slideshow ), drawerLayout ) setupActionBarWithNavController(navController, appBarConfiguration) navView.setupWithNavController(navController) recognizeResultTextView = findViewById(R.id.recognizeResult) val recognizeButton: Button = findViewById(R.id.recognizeButton) val uploadButton: Button = findViewById(R.id.recognizeOnlineButton) // 设置离线识别按钮的点击事件 recognizeButton.setOnClickListener { selectedBitMap?.let {bitmap -> val inferenceResult = staticProcessImage(bitmap) val inferenceTop3 = inferenceResult.split(\" \") val mappedResult = inferenceTop3.map { insectMapping[it] ?: \" \"} val returnText = \"离线识别的结果是：$mappedResult\" recognizeResultTextView.text = returnText } ?: run { recognizeResultTextView.text = \"请先选择图片\" } } // 设置上传识别按钮的点击事件 uploadButton.setOnClickListener { selectedBitMap?.let {bitmap -> val imageStream = bitmap2ByteArray(bitmap) uploadImage(imageStream) } ?: run{ recognizeResultTextView.text = \"请先选择图片\" } } } private fun bitmap2ByteArray(bitmap: Bitmap): ByteArray { val outputStream = ByteArrayOutputStream() bitmap.compress(Bitmap.CompressFormat.JPEG, 100, outputStream) return outputStream.toByteArray() } private fun uploadImage(byteArray: ByteArray){ val requestBody = okhttp3.RequestBody.create(MediaType.parse(\"image/jpeg\"), byteArray) val filePart = MultipartBody.Part.createFormData(\"image\", \"image.jpg\", requestBody) recognizeService.predict(filePart).enqueue(object : Callback<PredictResponse> { override fun onResponse( call: Call<PredictResponse>, response: Response<PredictResponse> ) { if(response.isSuccessful && response.body()?.success == true) {  val result = response.body()?.predictions  if(result == null){ Toast.makeText(this@MainActivity, \"上传图片成功，但未返回识别结果\", Toast.LENGTH_SHORT).show()  }else { val labels: List<String> = result.map { it.label } val mappedLabels = labels.map { insectMapping[it] ?: \" \"} val returnText = \"上传识别的结果是：$mappedLabels\" recognizeResultTextView.text = returnText  } }else {  Toast.makeText(this@MainActivity, \"上传图片失败\", Toast.LENGTH_SHORT).show() } } override fun onFailure(call: Call<PredictResponse>, t: Throwable) { Toast.makeText(this@MainActivity, \"请求失败\", Toast.LENGTH_SHORT).show() Log.e(\"MainActivity\", \"上传图片失败: ${t.message}\") } }) } override fun onCreateOptionsMenu(menu: Menu): Boolean { // Inflate the menu; this adds items to the action bar if it is present. menuInflater.inflate(R.menu.main, menu) return true } override fun onOptionsItemSelected(item: MenuItem): Boolean { when(item.itemId){ R.id.logout -> { val sharedPreferences = getSharedPreferences(\"AppPreferences\", MODE_PRIVATE) val editor = sharedPreferences.edit() editor.remove(\"token\") editor.apply() val intent = Intent(this, LoginActivity::class.java) startActivity(intent) finish() return true } } return super.onOptionsItemSelected(item) } override fun onSupportNavigateUp(): Boolean { val navController = findNavController(R.id.nav_host_fragment_content_main) return navController.navigateUp(appBarConfiguration) || super.onSupportNavigateUp() } fun setSelectedBitMap(bitmap: Bitmap){ selectedBitMap = bitmap }}

CMakeList

project(moth)cmake_minimum_required(VERSION 3.10.0)# 设置Android环境set(CMAKE_SYSTEM_NAME Android)set(CMAKE_ANDROID_NDK $ENV{ANDROID_NDK_HOME})set(CMAKE_ANDROID_STL_TYPE c++_static)# 设置 ncnn 库路径set(ncnn_DIR ${CMAKE_SOURCE_DIR}/ncnn/${ANDROID_ABI}/lib)# 设置opencv 库路径set(opencv_DIR ${CMAKE_SOURCE_DIR}/opencv/native)# 查找并连接libandroid.sofind_library(android-lib android)# 添加 ncnn 库add_library(ncnn SHARED IMPORTED)set_target_properties(ncnn PROPERTIES IMPORTED_LOCATION ${ncnn_DIR}/libncnn.so)# 添加opencv 库add_library(opencv SHARED IMPORTED)set_target_properties(opencv PROPERTIES IMPORTED_LOCATION ${opencv_DIR}/libs/${ANDROID_ABI}/libopencv_java4.so)include_directories(${opencv_DIR}/jni/include)# 添加cpp源码add_library(native-lib SHARED native-lib.cpp)# 添加C++标准库set(CMAKE_CXX_STANDARD 11)set(CMAKE_CXX_STANDARD_REQUIRED ON)# 链接 ncnn 库target_link_libraries(native-lib ${android-lib} ncnn opencv jnigraphics c++_shared)

native-lib.cpp

//// Created by Dell on 2025/2/20.////// Created by Dell on 2025/2/20.//#define STB_IMAGE_IMPLEMENTATION#include \"stb_image.h\"#include #include #include #include #include #include #include \"ncnn/arm64-v8a/include/ncnn/net.h\"// 中心裁切并归一化处理cv::Mat preprocessImage(const cv::Mat& inputImage, int targetWidth, int targetHeight) { cv::Mat resizedImage; cv::resize(inputImage, resizedImage, cv::Size(targetWidth, targetHeight)); // 将裁切后的图像转换为浮点型并归一化 cv::Mat normalizedImage; resizedImage.convertTo(normalizedImage, CV_32F, 1.0 / 255.0); // 归一化处理 cv::Mat channels[3]; cv::split(normalizedImage, channels); // 对每个通道进行归一化 for (int i = 0; i < 3; ++i) { channels[i] = (channels[i] - 0.485) / 0.229; // 第一个通道R if (i == 1) { channels[i] = (channels[i] - 0.456) / 0.224; // 第二个通道G } else if (i == 2) { channels[i] = (channels[i] - 0.406) / 0.225; // 第三个通道B } } // 合并通道 cv::merge(channels, 3, normalizedImage); return normalizedImage;}extern \"C\"JNIEXPORT jstring JNICALLJNICALLJava_com_example_moth_MainActivity_staticProcessImage(JNIEnv* env, jobject thiz, jobject bitmap) { // 获取 AssetManager jclass clazz = env->GetObjectClass(thiz); jfieldID assetManagerFieldID = env->GetFieldID(clazz, \"assetManager\", \"Landroid/content/res/AssetManager;\"); jobject assetManagerObj = env->GetObjectField(thiz, assetManagerFieldID); AAssetManager* assetManager = AAssetManager_fromJava(env, assetManagerObj); // 加载 .param 文件 AAsset* paramAsset = AAssetManager_open(assetManager, \"effivit.param\", AASSET_MODE_BUFFER); if (!paramAsset) { return env->NewStringUTF(\"Failed to open model.param\"); } // 读取 .param 文件内容 size_t paramSize = AAsset_getLength(paramAsset); char* paramBuffer = new char[paramSize]; AAsset_read(paramAsset, paramBuffer, paramSize); AAsset_close(paramAsset); // 加载 .bin 文件 AAsset* binAsset = AAssetManager_open(assetManager, \"effivit.bin\", AASSET_MODE_BUFFER); if (!binAsset) { delete[] paramBuffer; return env->NewStringUTF(\"Failed to open model.bin\"); } // 读取 .bin 文件内容 size_t binSize = AAsset_getLength(binAsset); char* binBuffer = new char[binSize]; AAsset_read(binAsset, binBuffer, binSize); AAsset_close(binAsset); // 创建 ncnn 网络 ncnn::Net net; int ret = net.load_param(assetManager, \"effivit.param\"); if (ret != 0) { delete[] paramBuffer; delete[] binBuffer; return env->NewStringUTF(\"Failed to load model.param\"); } ret = net.load_model(assetManager, \"effivit.bin\"); if (ret != 0) { delete[] paramBuffer; delete[] binBuffer; return env->NewStringUTF(\"Failed to load model.bin\"); } // 释放内存 delete[] paramBuffer; delete[] binBuffer; // 获取 Bitmap 信息 AndroidBitmapInfo info; void* pixels; int retBitmap; if ((retBitmap = AndroidBitmap_getInfo(env, bitmap, &info)) < 0) { return env->NewStringUTF(\"AndroidBitmap_getInfo() failed!\"); } if (info.format != ANDROID_BITMAP_FORMAT_RGBA_8888) { return env->NewStringUTF(\"Bitmap format is not RGBA_8888!\"); } if ((retBitmap = AndroidBitmap_lockPixels(env, bitmap, &pixels)) < 0) { return env->NewStringUTF(\"AndroidBitmap_lockPixels() failed!\"); } // 将 Bitmap 转换为 OpenCV Mat cv::Mat mat(info.height, info.width, CV_8UC4, pixels); cv::Mat mat3; cv::cvtColor(mat, mat3, cv::COLOR_RGBA2BGR); // 调整图像大小 int targetWidth = 224; int targetHeight = 224; cv::Mat resizedMat; //= preprocessImage(mat3, targetWidth, targetHeight); cv::resize(mat3, resizedMat, cv::Size(targetWidth, targetHeight)); // 将 Mat 转换为 ncnn::Mat ncnn::Mat in = ncnn::Mat::from_pixels(resizedMat.data, ncnn::Mat::PIXEL_BGR, targetWidth, targetHeight); // 进行推理 ncnn::Extractor ex = net.create_extractor(); ex.input(\"input.1\", in); ncnn::Mat out; ex.extract(\"1270\", out); // 释放 Bitmap 像素数据 AndroidBitmap_unlockPixels(env, bitmap); // 处理输出结果 // 假设张量 out 的形状为 (1, 13)，即 1 行 13 列 float* outputData = (float*)out.data; int numClasses = out.w; // 获取类别数量（13） // 找到概率最大的三个下标 std::vector<std::pair<float, int>> probIndexPairs; for (int i = 0; i < numClasses; i++) { probIndexPairs.push_back(std::make_pair(outputData[i], i)); } // 按概率值从大到小排序 std::sort(probIndexPairs.begin(), probIndexPairs.end(), [](const std::pair<float, int>& a, const std::pair<float, int>& b) { return a.first > b.first; }); // 获取概率最大的三个下标 std::string result; for (int i = 0; i < 3 && i < probIndexPairs.size(); i++) { result += std::to_string(probIndexPairs[i].second) + \" \"; } // 返回结果给调用方 return env->NewStringUTF(result.c_str());}

stb_image.h

在这里插入代码片