安卓JNI使用OpenCV

OpenCV也有Java数据结构的包，不过计算速度还是很慢，非不得已不使用此种方式调用OpenCV。使用NDK编写底层OpenCv的调用代码，使用JNI对代码进行封装，可以稍微提高一点效率。

参考链接：http://www.tuicool.com/articles/yaeeuu

安卓使用OpenCV注意事项：

一、 添加头文件包含：

对自己建立的SO包里面的JNI源文件，添加即将使用到的头文件包含：

#include <jni.h>

#include <string.h>
#include <stdio.h>
#include <android/log.h>

<u>#include "rec3D.h"</u>

#ifndef _Included_org_opencv_samples_fd_DetectionBasedTracker
#define _Included_org_opencv_samples_fd_DetectionBasedTracker
#ifdef __cplusplus
extern "C" {
#endif

//JNIEnv* jniEnv;
extern "C" jstring Java_com_example_feeljulygpsmap_FeelJulyActivity_careJuly(JNIEnv *env, jobject thiz) ;
extern "C" jint Java_com_example_feeljulygpsmap_FeelJulyActivity_careJulyIn(JNIEnv *env, jobject thiz,jint showCode) ;
extern "C" jintArray Java_com_example_feeljulygpsmap_FeelJulyActivity_careJulyArray(JNIEnv *env, jobject thiz,jintArray InCode) ;

#ifdef __cplusplus
}
#endif
#endif

使用到OpenCV的源文件：

#pragma once

#ifndef _REC3D_H
#define _REC3D_H

<u>#include <opencv2/core/core.hpp>
#include <opencv2/video/video.hpp>
#include <opencv2/calib3d/calib3d.hpp></u>

#include <iostream>
#include <vector>

#include <stdlib.h>

using namespace  cv;
using namespace std;

class MyCamera{

public:
cv::Mat intrinsic_Mat;
cv::Mat disCoeff;

二、在工程中添加OpenCV的目录包含和库引用

文件：Android.mk

LOCAL_PATH := $(call my-dir)

include $(CLEAR_VARS)
LOCAL_C_INCLUDES := C:\QT\OpenCV-3.0-android-sdk\sdk\native\jni\include

OPENCV_LIB_TYPE   := static

ifeq ("$(wildcard $(OPENCV_MK_PATH))","")
#try to load OpenCV.mk from default install location
include C:\QT\OpenCV-3.0-android-sdk\sdk\native\jni\OpenCV.mk
else
include $(OPENCV_MK_PATH)
endif

#include $(CLEAR_VARS)

LOCAL_MODULE    := feelJulyGpsMap
LOCAL_SRC_FILES := feelJulyGpsMap.cpp \
rec3D.cpp

#LOCAL_LDLIBS    := -landroid

LOCAL_LDLIBS += -L$(SYSROOT)/usr/lib -llog
include $(BUILD_SHARED_LIBRARY)

在此注意事项：

LOCAL_C_INCLUDES := C:\QT\OpenCV-3.0-android-sdk\sdk\native\jni\include

为OpenCV的C++ 头文件包含目录

include C:\QT\OpenCV-3.0-android-sdk\sdk\native\jni\OpenCV.mk

为OpenCV的库文件包含目录

三、使用OpenCV编译程序

snip..............................................

四、使用Android Native模式调试C++代码部分

snip.............................



备注：cv::solvePnP使用OpenCv解决多点透视问题！