Face Detection Using OCL (OPENCV) - c++

Question

I am trying to detect faces using the below code making use of GPU
#include <opencv\cv.h>
#include <opencv\highgui.h>
#include <iostream>
#include <stdio.h>
#include <opencv2\ocl\ocl.hpp>
std::string face_cascade = "C:\\opencv\\data\\haarcascades\\haarcascade_frontalface_alt.xml";
std::vector<cv::Rect> detectFaces(cv::Mat gray){
cv::ocl::oclMat oclGray;
std::vector<cv::Rect> faces;
cv::ocl::OclCascadeClassifier face_detector;
oclGray.upload(gray);
face_detector.load(face_cascade);
face_detector.detectMultiScale(oclGray, faces, 1.1, 3, 0|CV_HAAR_SCALE_IMAGE, cv::Size(30, 30), cv::Size(0, 0));
return faces;
}
int main(){
cv::VideoCapture webcam;
cv::Mat mainImage;
std::vector<cv::Rect> faces;
webcam.open(0);
cv::namedWindow("face",CV_WINDOW_AUTOSIZE);
while(webcam.isOpened()){
webcam.read(mainImage);
if(!mainImage.empty()){
cv::resize(mainImage,mainImage,cv::Size(640,480),0,0,1);
cv::Mat gray(mainImage);
cv::cvtColor(gray,gray,CV_BGR2GRAY);
cv::equalizeHist(gray,gray);
faces = detectFaces(gray);
for(unsigned int i=0;i<faces.size();i++){
cv::Rect f_rect = faces[i];
cv::rectangle(mainImage,f_rect,CV_RGB(255,0,0),1,8,0);
}
cv::imshow("face",mainImage);
}
cv::waitKey(40);
}
return 0;
}
I wasnt satisfied with t speed of the normal cascade classifier and thus coded for Ocl based classifier. The program gets started but shows error message:
I have installed APP SDK v 2.9.1
I am using Visual Studio 2012 express edition, Opencv 2.4.10
Where did I go wrong??
Thanks
EDIT>>
cv::ocl::oclMat oclGray;
oclGray.upload(gray);
The above code is causing error..

Answer 1

It looks like it fails on this line face_detector.load(face_cascade); (use debugger to make sure that i'm right). Make sure that the path is correct and that format of cascade file is valid, you may try to use different cascade as well and of course make sure that OCL is installed and configured correctly.