error: taking address of temporary[-fpermissive]

[JohnWong007]

#include "opencv/cv.hpp"
#include "opencv2/objdetect/objdetect.hpp"
#include "opencv2/highgui/highgui.hpp"
#include "opencv2/imgproc/imgproc.hpp"

#include <iostream>
#include <stdio.h>

using namespace std;
using namespace cv;

String cascadeName = "D:\\codeblockproject\\compare_twofacephotos\\haarcascade_frontalface_alt.xml";

IplImage* cutImage(IplImage* src,CvRect rect) {
cvSetImageROI(src, rect);
IplImage *dst = cvCreateImage(cvSize(rect.width, rect.height),src->depth,src->nChannels);

cvCopy(src,dst,0);
cvResetImageROI(src);
return dst;
}

IplImage* detect( Mat& img, CascadeClassifier&cascade, double scale)
{
int i = 0;
double t = 0;
vector<Rect> faces;
Mat gray, smallImg( cvRound (img.rows/scale),cvRound(img.cols/scale), CV_8UC1 );

cvtColor( img, gray, CV_BGR2GRAY );
resize( gray, smallImg, smallImg.size(), 0,0, INTER_LINEAR );
equalizeHist( smallImg, smallImg );

t = (double)cvGetTickCount();
cascade.detectMultiScale( smallImg, faces,1.3, 2, CV_HAAR_SCALE_IMAGE,Size(30, 30) );
t = (double)cvGetTickCount() - t;
printf( "detection time = %g ms\n", t/((double)cvGetTickFrequency()*1000.) );
for( vector<Rect>::const_iterator r =faces.begin(); r != faces.end(); r++, i++ )
{
IplImage* temp = cutImage(&(IplImage(img)), cvRect(r->x, r->y, r->width, r->height));
return temp;
}
return NULL;
}
//画直方图用
int HistogramBins = 256;
float HistogramRange1[2]={0,255};
float *HistogramRange[1]={&HistogramRange1[0]};
int CompareHist(IplImage* image1, IplImage*image2)
{
IplImage* srcImage;
IplImage* targetImage;
if (image1->nChannels != 1) {
srcImage = cvCreateImage(cvSize(image1->width, image1->height), image1->depth, 1);
cvCvtColor(image1, srcImage,CV_BGR2GRAY);
}
else{
srcImage = image1;
}
if (image2->nChannels != 1)
{
targetImage = cvCreateImage(cvSize(image2->width, image2->height), srcImage->depth, 1);
cvCvtColor(image2, targetImage,CV_BGR2GRAY);
}
else
{
targetImage = image2;
}

CvHistogram *Histogram1 = cvCreateHist(1,&HistogramBins, CV_HIST_ARRAY,HistogramRange);
CvHistogram *Histogram2 = cvCreateHist(1,&HistogramBins, CV_HIST_ARRAY,HistogramRange);

cvCalcHist(&srcImage, Histogram1);
cvCalcHist(&targetImage, Histogram2);

cvNormalizeHist(Histogram1, 1);
cvNormalizeHist(Histogram2, 1);

// CV_COMP_CHISQR,CV_COMP_BHATTACHARYYA这两种都可以用来做直方图的比较，值越小，说明图形越相似
printf("CV_COMP_CHISQR : %.4f\n",
cvCompareHist(Histogram1, Histogram2, CV_COMP_CHISQR));
printf("CV_COMP_BHATTACHARYYA : %.4f\n",

cvCompareHist(Histogram1, Histogram2,CV_COMP_BHATTACHARYYA));


// CV_COMP_CORREL, CV_COMP_INTERSECT这两种直方图的比较，值越大，说明图形越相似
printf("CV_COMP_CORREL : %.4f\n",cvCompareHist(Histogram1, Histogram2, CV_COMP_CORREL));
printf("CV_COMP_INTERSECT : %.4f\n",cvCompareHist(Histogram1, Histogram2,CV_COMP_INTERSECT));

cvReleaseHist(&Histogram1);
cvReleaseHist(&Histogram2);
if (image1->nChannels != 1) {
cvReleaseImage(&srcImage);
}
if (image2->nChannels != 1) {
cvReleaseImage(&targetImage);
}
return 0;
}
String srcImage = "D:\\codeblockproject\\compare_twofacephotos\\Tse1.jpg";
String targetImage = "D:\\codeblockproject\\compare_twofacephotos\\Tse2.jpg";
int main(int argc, char* argv[])
{
CascadeClassifier cascade;
namedWindow("image1");
namedWindow("image2");
if( !cascade.load( cascadeName ) )
{
return -1;
}

Mat srcImg, targetImg;
IplImage* faceImage1;
IplImage* faceImage2;
srcImg = imread(srcImage);
targetImg = imread(targetImage);
faceImage1 = detect(srcImg, cascade, 1);
if (faceImage1 == NULL) {
return -1;
}
//cvSaveImage("d:\\face.jpg", faceImage1, 0);


faceImage2 = detect(targetImg, cascade, 1);
if (faceImage2 == NULL) {
return -1;
}
//cvSaveImage("d:\\face1.jpg", faceImage2,0);
imshow("image1", Mat(faceImage1));
imshow("image2", Mat(faceImage2));

CompareHist(faceImage1, faceImage2);
cvWaitKey(0);
cvReleaseImage(&faceImage1);
cvReleaseImage(&faceImage2);
return 0;
}

错误出在 IplImage* temp = cutImage(&(IplImage(img)), cvRect(r->x, r->y, r->width, r->height));
error: taking address of temporary[-fpermissive]

[JiMoKuangXiangQu]

引用 楼主 h976144283 的回复:

#include "opencv/cv.hpp" #include "opencv2/objdetect/objdetect.hpp" #include "opencv2/highgui/highgui.hpp" #include "opencv2/imgproc/imgproc.hpp" #include <iostream> #include <stdio.h> using namespace std; using namespace cv; String cascadeName = "D:\\codeblockproject\\compare_twofacephotos\\haarcascade_frontalface_alt.xml"; IplImage* cutImage(IplImage* src,CvRect rect) { cvSetImageROI(src, rect); IplImage *dst = cvCreateImage(cvSize(rect.width, rect.height),src->depth,src->nChannels); cvCopy(src,dst,0); cvResetImageROI(src); return dst; } IplImage* detect( Mat& img, CascadeClassifier&cascade, double scale) { int i = 0; double t = 0; vector<Rect> faces; Mat gray, smallImg( cvRound (img.rows/scale),cvRound(img.cols/scale), CV_8UC1 ); cvtColor( img, gray, CV_BGR2GRAY ); resize( gray, smallImg, smallImg.size(), 0,0, INTER_LINEAR ); equalizeHist( smallImg, smallImg ); t = (double)cvGetTickCount(); cascade.detectMultiScale( smallImg, faces,1.3, 2, CV_HAAR_SCALE_IMAGE,Size(30, 30) ); t = (double)cvGetTickCount() - t; printf( "detection time = %g ms\n", t/((double)cvGetTickFrequency()*1000.) ); for( vector<Rect>::const_iterator r =faces.begin(); r != faces.end(); r++, i++ ) { IplImage* temp = cutImage(&(IplImage(img)), cvRect(r->x, r->y, r->width, r->height)); return temp; } return NULL; } //画直方图用 int HistogramBins = 256; float HistogramRange1[2]={0,255}; float *HistogramRange[1]={&HistogramRange1[0]}; int CompareHist(IplImage* image1, IplImage*image2) { IplImage* srcImage; IplImage* targetImage; if (image1->nChannels != 1) { srcImage = cvCreateImage(cvSize(image1->width, image1->height), image1->depth, 1); cvCvtColor(image1, srcImage,CV_BGR2GRAY); } else{ srcImage = image1; } if (image2->nChannels != 1) { targetImage = cvCreateImage(cvSize(image2->width, image2->height), srcImage->depth, 1); cvCvtColor(image2, targetImage,CV_BGR2GRAY); } else { targetImage = image2; } CvHistogram *Histogram1 = cvCreateHist(1,&HistogramBins, CV_HIST_ARRAY,HistogramRange); CvHistogram *Histogram2 = cvCreateHist(1,&HistogramBins, CV_HIST_ARRAY,HistogramRange); cvCalcHist(&srcImage, Histogram1); cvCalcHist(&targetImage, Histogram2); cvNormalizeHist(Histogram1, 1); cvNormalizeHist(Histogram2, 1); // CV_COMP_CHISQR,CV_COMP_BHATTACHARYYA这两种都可以用来做直方图的比较，值越小，说明图形越相似 printf("CV_COMP_CHISQR : %.4f\n", cvCompareHist(Histogram1, Histogram2, CV_COMP_CHISQR)); printf("CV_COMP_BHATTACHARYYA : %.4f\n", cvCompareHist(Histogram1, Histogram2,CV_COMP_BHATTACHARYYA)); // CV_COMP_CORREL, CV_COMP_INTERSECT这两种直方图的比较，值越大，说明图形越相似 printf("CV_COMP_CORREL : %.4f\n",cvCompareHist(Histogram1, Histogram2, CV_COMP_CORREL)); printf("CV_COMP_INTERSECT : %.4f\n",cvCompareHist(Histogram1, Histogram2,CV_COMP_INTERSECT)); cvReleaseHist(&Histogram1); cvReleaseHist(&Histogram2); if (image1->nChannels != 1) { cvReleaseImage(&srcImage); } if (image2->nChannels != 1) { cvReleaseImage(&targetImage); } return 0; } String srcImage = "D:\\codeblockproject\\compare_twofacephotos\\Tse1.jpg"; String targetImage = "D:\\codeblockproject\\compare_twofacephotos\\Tse2.jpg"; int main(int argc, char* argv[]) { CascadeClassifier cascade; namedWindow("image1"); namedWindow("image2"); if( !cascade.load( cascadeName ) ) { return -1; } Mat srcImg, targetImg; IplImage* faceImage1; IplImage* faceImage2; srcImg = imread(srcImage); targetImg = imread(targetImage); faceImage1 = detect(srcImg, cascade, 1); if (faceImage1 == NULL) { return -1; } //cvSaveImage("d:\\face.jpg", faceImage1, 0); faceImage2 = detect(targetImg, cascade, 1); if (faceImage2 == NULL) { return -1; } //cvSaveImage("d:\\face1.jpg", faceImage2,0); imshow("image1", Mat(faceImage1)); imshow("image2", Mat(faceImage2)); CompareHist(faceImage1, faceImage2); cvWaitKey(0); cvReleaseImage(&faceImage1); cvReleaseImage(&faceImage2); return 0; } 错误出在 IplImage* temp = cutImage(&(IplImage(img)), cvRect(r->x, r->y, r->width, r->height)); error: taking address of temporary[-fpermissive]

错误提示很明显，语句：

IplImage* temp = cutImage(&(IplImage(img)), cvRect(r->x, r->y, r->width, r->height));

中 &(IplImage(img)) 操作取了临时变量的地址。返回后临时变量已经“消失”了，你不能再使用了。

[JohnWong007]

我查了相关的问题，好像是加const啥的 ，但是我实在是个菜鸟，你知道如何修改否？

[JohnWong007]

why？我想要的是解决办法，而不是指出错误而已。

[MrMoment]

解决方法是把临时变量赋值到一个声明的变量，然后取址 IplImage tmp_image= IplImage(img); IplImage* temp = cutImage(&tmp_image, cvRect(r->x, r->y, r->width, r->height));