Android将camera获取到的YuvData在jni中转化为Mat方法

/*
* ImageProcessing.cpp
*  实时显示canny算子结果
*/
#include <jni.h>
 
#include <opencv2/core/core.hpp>
#include <opencv2/imgproc/imgproc_c.h>
#include <opencv2/opencv.hpp>
 
 
using namespace std;
using namespace cv;
 
 
Mat * mCanny = NULL;
 
extern "C"
jboolean
Java_my_project_MyRealTimeImageProcessing_CameraPreview_ImageProcessing(
		JNIEnv* env, jobject thiz,
		jint width, jint height,
		jbyteArray NV21FrameData, jintArray outPixels)
{
	jbyte * pNV21FrameData = env->GetByteArrayElements(NV21FrameData, 0); //输入yuv数据 
	jint * poutPixels = env->GetIntArrayElements(outPixels, 0);	//输出结果的int数据
	if ( mCanny == NULL )
	{
		mCanny = new Mat(height, width, CV_8UC1);
	}
	Mat mGray(height, width, CV_8UC1, (unsigned char *)pNV21FrameData);	//构建灰度图时构造函数
	Mat mResult(height, width, CV_8UC4, (unsigned char *)poutPixels);
	IplImage srcImg = mGray;
	IplImage CannyImg = *mCanny;
	IplImage ResultImg = mResult;
 
	cvCanny(&srcImg, &CannyImg, 80, 100, 3);
	cvCvtColor(&CannyImg, &ResultImg, CV_GRAY2BGRA);
	env->ReleaseByteArrayElements(NV21FrameData, pNV21FrameData, 0);
	env->ReleaseIntArrayElements(outPixels, poutPixels, 0);
	return true;
}

Y = width*height

U = Y/4

v = Y/4

JNIEXPORT int JNICALL Java_com_ProjectName_nativecaller_ClassName_readYUV420SP(JNIEnv *env, jclass clz, jbyteArray yuv,jint len,jint height,jint width)
{
 
	jbyte * pBuf = (jbyte*)env->GetByteArrayElements(yuv, 0);
 
	Mat image(height + height/2,width,CV_8UC1,(unsigned char *)pBuf);	//注意这里是height+height/2
	Mat mBgr;
	cvtColor(image, mBgr, CV_YUV2BGR_NV21);
	imwrite("/mnt/sdcard/readYuv.jpg",mBgr);
	env->ReleaseByteArrayElements(yuv, pBuf, 0);  
	return 0;
}