I want to extract some harriscorners from an image and get FREAK descriptors. Here is how I try to do it: (The passed variables are globally defined.)
void computeFeatures(cv::Mat &src, std::vector<cv::KeyPoint> &keypoints, cv::Mat &desc ) {
cv::Mat featureSpace;
featureSpace = cv::Mat::zeros( src.size(), CV_32FC1 );
//- Detector parameters
int blockSize = 3;
int apertureSize = 3;
double k = 0.04;
//- Detecting corners
cornerHarris( src, featureSpace, blockSize, apertureSize, k, cv::BORDER_DEFAULT );
//- Thresholding featureSpace
keypoints.clear();
nonMaximumSuppression(featureSpace, keypoints, param.nms_n);
//- compute FREAK-descriptor
cv::FREAK freak(false, false, 22.0f, 4);
freak.compute(src, keypoints, desc);
}
I can compile it with Visual Studio 12 as well as Matlab R2013b via mex. When I run it as "stand alone" (.exe) it works just fine. When I try to execute it via Matlab it fails with this message:
A buffer overrun has occurred in MATLAB.exe which has corrupted the program's internal state. Press Break to debug the program or Continue to terminate the program.
I mexed with the debug option '-g' and attached VisualStudio to Matlab to be able to get closer to the error:
After nonMaximumSuppression() the size of keypoints is 233 when I jump into freak.compute() the size is suddenly 83 with "random" values stored.
The actual error is then in KeyPointsFilter::runByKeypointSize when keypoints should be erased.
in keypoint.cpp line 256:
void KeyPointsFilter::runByKeypointSize( vector<KeyPoint>& keypoints, float minSize, float maxSize )
{
CV_Assert( minSize >= 0 );
CV_Assert( maxSize >= 0);
CV_Assert( minSize <= maxSize );
keypoints.erase( std::remove_if(keypoints.begin(), keypoints.end(), SizePredicate(minSize, maxSize)),
keypoints.end() );
}
Is there some error I'm making with passing the keyPoint-vector? Has anybody run into a similar problem?
EDIT:
Here is the mex-file with the additional library "opencv_matlab.hpp" taken from MatlabCentral
#include "opencv_matlab.hpp"
void mexFunction (int nlhs,mxArray *plhs[],int nrhs,const mxArray *prhs[]) {
// read command
char command[128];
mxGetString(prhs[0],command,128);
if (!strcmp(command,"push") || !strcmp(command,"replace")) {
// check arguments
if (nrhs!=1+1 && nrhs!=1+2)
mexErrMsgTxt("1 or 2 inputs required (I1=left image,I2=right image).");
if (!mxIsUint8(prhs[1]) || mxGetNumberOfDimensions(prhs[1])!=2)
mexErrMsgTxt("Input I1 (left image) must be a uint8_t matrix.");
// determine input/output image properties
const int *dims1 = mxGetDimensions(prhs[1]);
const int nDims1 = mxGetNumberOfDimensions(prhs[1]);
const int rows1 = dims1[0];
const int cols1 = dims1[1];
const int channels1 = (nDims1 == 3 ? dims1[2] : 1);
// Allocate, copy, and convert the input image
// @note: input is double
cv::Mat I1_ = cv::Mat::zeros(cv::Size(cols1, rows1), CV_8UC(channels1));
om::copyMatrixToOpencv<uchar>((unsigned char*)mxGetPr(prhs[1]), I1_);
// push back single image
if (nrhs==1+1) {
// compute features and put them to ring buffer
pushBack(I1_,!strcmp(command,"replace"));
// push back stereo image pair
} else {
if (!mxIsUint8(prhs[2]) || mxGetNumberOfDimensions(prhs[2])!=2)
mexErrMsgTxt("Input I2 (right image) must be a uint8_t matrix.");
// determine input/output image properties
const int *dims2 = mxGetDimensions(prhs[2]);
const int nDims2 = mxGetNumberOfDimensions(prhs[2]);
const int rows2 = dims2[0];
const int cols2 = dims2[1];
const int channels2 = (nDims2 == 3 ? dims2[2] : 1);
// Allocate, copy, and convert the input image
// @note: input is double
cv::Mat I2_ = cv::Mat::zeros(cv::Size(cols2, rows2), CV_8UC(channels2));
om::copyMatrixToOpencv<uchar>((unsigned char*)mxGetPr(prhs[2]), I2_);
// check image size
if (dims1_[0]!=dims2_[0] || dims1_[1]!=dims2_[1])
mexErrMsgTxt("Input I1 and I2 must be images of same size.");
// compute features and put them to ring buffer
pushBack(I1_,I2_,!strcmp(command,"replace"));
}
}else {
mexPrintf("Unknown command: %s\n",command);
}
}
And here is an additional part of the main cpp project.
std::vector<cv::KeyPoint> k1c1, k2c1, k1p1, k2p1; //KeyPoints
cv::Mat d1c1, d2c1, d1p1, d2p1; //descriptors
void pushBack (cv::Mat &I1,cv::Mat &I2,const bool replace) {
// sanity check
if (I1.empty()) {
cerr << "ERROR: Image empty!" << endl;
return;
}
if (replace) {
//if (!k1c1.empty())
k1c1.clear(); k2c1.clear();
d1c1.release(); d2c1.release();
} else {
k1p1.clear(); k2p1.clear();
d1p1.release(); d2p1.release();
k1p1 = k1c1; k2p1 = k2c1;
d1c1.copyTo(d1p1); d2c1.copyTo(d2p1);
k1c1.clear(); k2c1.clear();
d1c1.release(); d2c1.release();
}
// compute new features for current frame
computeFeatures(I1,k1c1,d1c1);
if (!I2.empty())
computeFeatures(I2,k2c1,d2c1);
}
And here is how I call the mex-file from Matlab
I1p = imread('\I1.bmp');
I2p = imread('\I2.bmp');
harris_freak('push',I1p,I2p);
Hope this helps...
