opencv全稱open source compute vision,開源的視覺庫

一.準備工作

匯入opencv的步驟還是相對簡單,準備步驟分為以下三步:

1. 將OpenCV-android-sdk/sdk/native/libs拷貝到工程的jniLibs
2. 將OpenCV-android-sdk/sdk/native/jni/include拷貝到src/main/cpp目錄（cpp目錄不存在就新建一個）

這時候，你的工程目錄應該如下圖:

二.建立include和so庫的繫結關係,CMakeLists.txt

cmake_minimum_required(VERSION 3.6)
set(CMAKE_VERBOSE_MAKEFILE on)
 

set(libs "${CMAKE_SOURCE_DIR}/src/main/jniLibs")
add_library(native-lib
        SHARED
        src/main/cpp/Hello.cpp ) #新增.c原始檔

include_directories(src/main/cpp/include) #新增標頭檔案的位置

#新增庫物件，並設定引用方式
add_library(libopencv_java3 SHARED IMPORTED )
#設定libopencv_java3庫的位置
set_target_properties(libopencv_java3 PROPERTIES
        IMPORTED_LOCATION "${libs}/${ANDROID_ABI}/libopencv_java3.so"
 
)

target_link_libraries( # Specifies the target library.
        native-lib -ljnigraphics libopencv_java3
        # Links the target library to the log library
        # included in the NDK.
        ${log-lib} )

三.呼叫opencv的方法

先看MainActivity.java

public class MainActivity extends AppCompatActivity {
 


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        TextView contentTv = findViewById(R.id.tv_content);
        contentTv.setText(getVersion());
    }
    static {
        System.loadLibrary("native-lib");
    }
    public native String getVersion();
}

Hello.h會Include opencv的標頭檔案

#ifndef PRACTICLE_HELLO_H
#define PRACTICLE_HELLO_H

#include <jni.h>
#include <android/bitmap.h>
#include <opencv/cv.h>
#include <opencv2/opencv.hpp>
#include <opencv2/imgproc/imgproc.hpp>
using namespace cv;
extern "C"
JNIEXPORT jstring JNICALL
Java_com_example_a6_1opencv2_MainActivity_getVersion(JNIEnv *env, jobject instance);
#endif //PRACTICLE_HELLO_H

在看Hello.cpp

#include <jni.h>
#include "Hello.h"

#ifdef __cplusplus
extern "C" {
#endif

JNIEXPORT jstring JNICALL
Java_com_example_a6_1opencv2_MainActivity_getVersion(JNIEnv *env, jobject instance) {
    const char *version = CV_VERSION;
    return env->NewStringUTF(version);;
} ;

#ifdef __cplusplus
}
#endif

四.執行結果