title: image encryption using XOR
body: <p>Okay I am working on a video processing project and this include encryption of each frame and writing it to a file (outputenc.avi). I use a key.jpg to encrypt each file using XOR operation and its going well but the problem is during decryption I am getting a noisy original image the key and the frame under process are GRAY SCALE images with dimension 384*288. </p>
  
  <p>encyption</p>
  
  <pre><code>capWebcam.read(matOriginal);
  if(matOriginal.empty()==true)
      return;
  cv::Mat temp;
  cv::resize(matOriginal,matOriginal,dsize,0,0,cv::INTER_CUBIC);
  cv::cvtColor(matOriginal,matProcessed,CV_BGR2GRAY);
  
  cv::bitwise_xor(matProcessed,key,temp);
  output_enc_cap.write(temp);
  </code></pre>
  
  <p>decryption</p>
  
  <pre><code>capfile.read(temp);
  if(temp.empty()==true)
        return;
  
  cvtColor(temp,temp,CV_BGR2GRAY);
  cv::bitwise_xor(temp,key,temp);
  </code></pre>