error C3861: 'getGaborKernel': identifier not found - c++

Question

I am trying to build the following code, but It failed because of the following error
error C3861: 'getGaborKernel': identifier not found
I have included the required header files and lib files. What could be the problem?
#include "stdafx.h"
#include <opencv2/core/core.hpp>
#include <opencv2/imgproc/imgproc.hpp>
#include <opencv2/highgui/highgui.hpp>
#include <math.h>
using namespace cv;
using namespace std;
int main(int argc, char* argv[])
{
Mat in = imread("1.jpg",0); // load grayscale
Mat dest;
Mat src_f;
in.convertTo(src_f,CV_32F);
extern ostream cerr;
int kernel_size = 31;
double sig = 1, th = 0, lm = 1.0, gm = 0.02, ps = 0;
cv::Mat kernel =
getGaborKernel(cv::Size(kernel_size,kernel_size),sig, th, lm, gm,
ps);
cv::filter2D(src_f, dest, CV_32F, kernel);
cerr << dest(Rect(30,30,10,10)) << endl; // peek into the data
Mat viz;
dest.convertTo(viz,CV_8U,1.0/255.0);
imshow("k",kernel);
imshow("d",viz);
waitKey();
return 0;
}

Answer 1

When C++ misses a prototype it issues an error. Your source obviously didn't include the header file with the appropriate prototype or the prototype is hidden by #ifdefs.
Lookup the Header file that you expect that it contains the prototy of getGaborKernel.
Check the option Show includes to see what header files are actually included. Verify the header found in the first step is in the list.
Check the option Preprocess to a file to see what the preprocessor outputs after processing all #ifdefs in the generated .i file. Check why the prototype isn't in the output.
Uncheck both options after you have found the problem. That's important for the Preprocess to a file option to get a .obj file instead of the .i.