I have extracted LBP Texture features on an image by splitting the image into small cells and then calculating LBP for each sub-image and then latter concatenating spatial histograms of each sub-image following the [Philip Code](https://github.com/bytefish/opencv). I push these spatial histograms to a `vector`. I understand my spatial texture features are now contained in the histograms.
The problem I have is, I want to prepare this texture feature vector for training SVM. I convert the `vectorhists` of histograms to a row `Mat` where each row represent a sample. I use the code below to convert to row `Mat`.
Mat cv::asRowMatrix(const vector& src, int rtype, double alpha, double beta) {
// number of samples
size_t n = src.size();
// return empty matrix if no matrices given
if (n == 0)
return Mat();
// dimensionality of (reshaped) samples
size_t d = src[0].total();
// create data matrix
Mat data(n, d, rtype);
// now copy data
for (int i = 0; i < n; i++) {
// make sure data can be reshaped, throw exception if not!
if (src[i].total() != d) {
string error_message = format("Wrong number of elements in matrix #%d! Expected %d was %d.", i, d, src[i].total());
CV_Error(CV_StsBadArg, error_message);
}
// get a hold of the current row
Mat xi = data.row(i);
// make reshape happy by cloning for non-continuous matrices
if (src[i].isContinuous()) {
src[i].reshape(1, 1).convertTo(xi, rtype, alpha, beta);
}
else {
src[i].clone().reshape(1, 1).convertTo(xi, rtype, alpha, beta);
}
}
return data;}
When I do this as `Mat data = asRowMatrix(hists, CV_32F, 1, 0)` the matrix `data` comes with same values in each column, showing that all the images are identical. I get the same results if I use LBP image itself instead of its histogram. I would like to prepare LBP texture for training SVM. I have spent weeks figuring out this but am now stuck. Kindly help. Regards
This is how am filling the vector with the code below
string path = ".\\Images\\*.JPG"; //path to my images
vector names; //hold all URLs to images
cv::glob(path, names, false); //Reading URLs to names
//Loop through names, load image and calculate lbp and hists
vector hists;
Mat img;
Mat lbp;
Mat hist;
for(int i = 0; i < names.size(); i++)
{
img = imread(names[i]);
cvtColor(img, img, CV_BGR2GRAY);
lbp::OLBP(img, lbp); //call OLBP function in Phillip code
lbp::spatial_histogram(lbp, hist, 256, Size(10, 10)); //Call to spatial histograms function in Phillip code
hists.push_back(hist); //push back histogram of this image to vector of mat
}
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