OpenCV的預期構造，desctructor或類型轉換

Question

當我編譯下面的代碼，我收到以下錯誤：

./main.cpp:150: error: expected constructor, destructor, or type conversion before ‘(’ token <br> 
../main.cpp:154: error: expected constructor, destructor, or type conversion before ‘(’ token 
../main.cpp:156: error: expected constructor, destructor, or type conversion before ‘(’ token 
../main.cpp:158: error: expected constructor, destructor, or type conversion before ‘(’ token <br> 

但代碼看起來還好。 他有

cvReleaseVideoWriter(&writer); 
cvDestroyWindow("monoimage"); 
cvReleaseCapture(&capture); 

程序問題：

#include "iostream" 
#include "stdlib.h" 
#include "stdio.h" 
#include "cv.h" 
#include "highgui.h" 
#include "cstring"/*the includes*/ 

/*You may change the values of the sthreshold and hlower and hupper to get different results....*/ 
const int sthreshold=210; 
const double hlower=178; 
const double hupper=3; 

/*Note:The detection algorithm is the same as the one you can find in one of my previous posts 

The same algorithm is copied from that post and pasted in this 
post only the values of the "sthreshold" and the "hupper" and the "hlower" are different....*/ 

int main() 

{ 
int i,j,k;//for iterations 
int height,width,step,channels;/*HSV means the frame after color conversion*/ 
int heightmono,widthmono,stepmono,channelsmono;/*mono means the frame which has the monochrome image*/ 
const char string1[]="monoimg.avi";/*This is the name of the video which would be the outcome of the blob detection program..*/ 

uchar *data,*datamono; 

i=j=k=0; 

IplImage *frame = 0; 

int key = 0;/*Initializing the capture from the video...*/ 

CvCapture* capture = cvCreateFileCapture("partofvideo3.avi"); 

double fps = cvGetCaptureProperty (/*getting the capture properties......the frame rate..*/ 
capture,CV_CAP_PROP_FPS); 

CvSize size = cvSize(

(int)cvGetCaptureProperty(capture, CV_CAP_PROP_FRAME_WIDTH), 

(int)cvGetCaptureProperty(capture, CV_CAP_PROP_FRAME_HEIGHT) 

); 

CvVideoWriter* writer=cvCreateVideoWriter(string1, CV_FOURCC('D','I','V','X'),fps,size) ; 

/* always check */ 

if (!capture) { 

fprintf (stderr, "Cannot open video file!\n"); 

return(1); 

} 

height = frame->height; 

width = frame->width; 

step = frame->widthStep; 

channels = frame->nChannels; 

data = (uchar *)frame->imageData; 

/* create a window for the video,one for the monochrome image and the other for the original frame */ 

cvNamedWindow("monoimage", CV_WINDOW_AUTOSIZE); 

cvNamedWindow("original frame", CV_WINDOW_AUTOSIZE); 

for (;;) {/*keep looping till we are out of frames...*/ 

if (!cvGrabFrame(capture)) { 

break; 

} 

/*colimgbot---means color image of the bot*/ 

frame = cvRetrieveFrame(capture); 

IplImage *colimgbot = cvCreateImage(cvGetSize(frame), 8, 3); 

IplImage *monoimgbot = cvCreateImage(cvGetSize(frame), 8, 1); 

//------------------------------------------------------------------ 

cvCvtColor(frame,frame,CV_RGB2HSV);/*Converting the color space of the Video....*/ 

/*I have explained this loop in the previous program....*/ 

for(i=0;i< (height);i++) 
{ 
for(j=0;j<(width);j++) 
{ 
if((data[(height-i)*step+j*channels]<=hlower) && (data[(height-i)*step+j*channels]>=hupper)) 
{ 
if((data[(height-i)*step+j*(channels)+1])>sthreshold) 
/*"height-i" because if we use only "i" we were getting vertically inverted result...hence reinverting the same 
would do the required....*/ 

datamono[i*stepmono+j*channelsmono]=255; 
else 
datamono[i*stepmono+j*channelsmono]=0;} 
else datamono[i*stepmono+j*channelsmono]=0; 
}} 

/*Please check these links for the explanation of the erosion and dilation functions 

http://www.dca.fee.unicamp.br/dipcourse/html-dip/c9/s4/front-page.html*/ 

/*so now the last parameter in the function indicates how many times you want to apply dilation 
or erosion*/ 

cvErode(monoimgbot,monoimgbot,0,14); 
cvDilate(monoimgbot,monoimgbot,0,15); 

/*here i have experimented with the values by changing them...and i have found 

that i come to a good result by applying erosion 14 times and dilation 15 times 
you can comment/uncomment play with the values and see what is going on 
Sometimes you will find the areas which are shining in the image also get detected... 

Please think why and then try to post a comment the best commment would get visible on this page*/ 

cvWriteFrame(writer, monoimgbot);/*Write the monochrome video to the writer.. 

to save the results of the video extract*/ 

cvShowImage("original frame", frame); 

cvShowImage("monoimage", monoimgbot); 

if((cvWaitKey(10) & 255) == 27) break; 

} 

} 

/* free memory */ 

cvReleaseVideoWriter(&writer); 

//cvDestroyWindow("original frame"); 

cvDestroyWindow("monoimage"); 

cvReleaseCapture(&capture); 

exit(0); 

Answer 1

如果您想縮進代碼，它可能會幫助你找到這樣的問題。將main（或任何其他單一功能）保持在中途合理的長度也可能有幫助。從外觀看，這個代碼：

cvReleaseVideoWriter(&writer); 

//cvDestroyWindow("original frame"); 

cvDestroyWindow("monoimage"); 

cvReleaseCapture(&capture); 

exit(0); 

...（在你發佈的結尾處）是所有函數的外部。這樣的代碼必須在函數內部。

Answer 2

有一個額外的{，應該在年底：

if((cvWaitKey(10) & 255) == 27) break; 

} 

} <--- This should be in the end of the program. 

/* free memory */ 

這編譯：

 if ((cvWaitKey(10) & 255) == 27) 
      break; 

    } 

    /* free memory */ 
    cvReleaseVideoWriter(&writer); 
    cvDestroyWindow("original frame"); 
    cvDestroyWindow("monoimage"); 
    cvReleaseCapture(&capture); 

    exit(0); 
}