JAVA应用JNI调用OpenCV实现人脸检测
1.JAVA的JNI部分
调用JNI的基类

package lveyo.bcndyl.jni.opencv;public class JNIBase {public JNIBase(){}public JNIBase(String libraryName){loadLibrary(libraryName);}private static void loadLibrary(String libraryName){System.loadLibrary(libraryName);}}

实现这个基类

package lveyo.bcndyl.jni.opencv;public class JNIOpencv extends JNIBase{public JNIOpencv (String libraryName){super(libraryName);}public JNIOpencv(){System.loadLibrary("jniOpenCV");}    public native int[] detectFace(int minFaceWidth, int minFaceHeight,                                   String cascade, String filename);}

类中定义了一个detectFace方法，是要用C来实现的。

编译好这个类后，要用在命令行用javah命令生成需要的.h的头文件：
/* DO NOT EDIT THIS FILE - it is machine generated */#include <jni.h>/* Header for class lveyo_bcndyl_jni_opencv_JNIOpencv */#ifndef _Included_lveyo_bcndyl_jni_opencv_JNIOpencv#define _Included_lveyo_bcndyl_jni_opencv_JNIOpencv#ifdef __cplusplusextern "C" {#endif/* * Class: lveyo_bcndyl_jni_opencv_JNIOpencv * Method: detectFace * Signature: (IILjava/lang/String;Ljava/lang/String;)[I */JNIEXPORT jintArray JNICALL Java_lveyo_bcndyl_jni_opencv_JNIOpencv_detectFace (JNIEnv *, jobject, jint, jint, jstring, jstring);#ifdef __cplusplus}#endif#endif

2.C程序部分
按照http://www.opencv.org.cn/index.php/Template:Install安装OpenCV并配置相应的开发环境，我这里用的是VS2005，同时要将JDK中的include目录和include/win32目录都加入到VS2005的Include Files中。
新建一个win32 MFC DLL项目jniOpenCV，把刚才生成的lveyo_bcndyl_jni_opencv_JNIOpencv.h头文件加入到项目，并且修改jniOpenCV.cpp文件：

#include "stdafx.h"#include <jni.h>#include "lveyo_bcndyl_jni_opencv_JNIOpencv.h"#include "cv.h"#include "highgui.h"JNIEXPORT jintArray JNICALL Java_lveyo_bcndyl_jni_opencv_JNIOpencv_detectFace  (JNIEnv *env, jobject obj, jint width, jint height, jstring cascade, jstring filename){const char *str_cascade, *str_filename;str_cascade = env->GetStringUTFChars(cascade, false);str_filename = env->GetStringUTFChars(filename, false);jintArray faceArray;CvHaarClassifierCascade *cv_cascade = (CvHaarClassifierCascade*)cvLoad( str_cascade );IplImage *image = cvLoadImage( str_filename, 1 );if(image!=0){CvMemStorage* storage = cvCreateMemStorage(0);CvSeq* faces;//double t = (double)cvGetTickCount();/* use the fastest variant */faces = cvHaarDetectObjects( image, cv_cascade, storage, 1.2, 2,                                   CV_HAAR_DO_CANNY_PRUNING, cvSize(width, height) );//t = (double)cvGetTickCount() - t;        //printf( "detection time = %gms\n", t/((double)cvGetTickFrequency()*1000.) );const int total = faces->total;faceArray = env-> NewIntArray(4*total);jint faceBuf[4];for( int i = 0; i < total; i++ ){CvRect face_rect = *(CvRect*)cvGetSeqElem( faces, i );int pointX = face_rect.x;int pointY = face_rect.y;int faceWidth = face_rect.width;int faceHeight = face_rect.height;//printf("i %d, x %d, y %d, width %d, height %d\n",                        //        i,pointX,pointY,faceWidth,faceHeight);faceBuf[0] = pointX;faceBuf[1] = pointY;faceBuf[2] = faceWidth;faceBuf[3] = faceHeight;env->SetIntArrayRegion(faceArray,i*4,4,faceBuf);}cvReleaseMemStorage( &storage );cvReleaseImage( &image );}cvReleaseHaarClassifierCascade( &cv_cascade );    env->ReleaseStringUTFChars(cascade, str_cascade);env->ReleaseStringUTFChars(filename, str_filename);return faceArray;}

编译生成jniOpenCV.dll。此处的检测代码是根据OpenCV的文档和示例程序修改，由于本人对c++程序不是很熟练，所以对此段代码是否会有潜在危险和内存泄露不是很肯定，还请熟悉c使用的朋友帮忙检查一下。
别忘记将生成的jniOpenCV.dll文件复制到%JAVA_HOME%/bin中，如果在没安装OpenCV的机器上运行，还需要将OpenCV安装目录中bin目录下所有dll文件一起复制到%JAVA_HOME%/bin中。

3.实现JAVA的调用

package lveyo.bcndyl.jni.opencv;public class Test {public static void main(String[] args) {//初始化JNI调用类JNIOpencvJNIOpencv open = new JNIOpencv("jniOpenCV");//要检测的图片文件String filename = "d:/80010.jpg";//OpenCv提供的人间的特征文件String cascade = "d:/haarcascade_frontalface_alt2.xml";//人脸检测，前两个参数为可检测的最小人脸的宽度和高度//返回值为人脸在图中的坐标和宽高，{x, y, width, height}int[] faces = open.detectFace(40, 40, cascade, filename);if(faces != null && faces.length!=0){//返回的人脸总数System.out.println( "faces " + faces.length/4 );//分别输出每个人脸的坐标信息for (int temp : faces) {System.out.println(temp);}}}}

11 楼 shun1 2012-09-24 您好啊，您能把邮箱给我吗？我有问题可以请教你啊。