Opencv.2.computer.vision.application.programming.cookbook--efficient scanning of continuous images

#include <opencv2\opencv.hpp>void colorreduce (cv::mat &image, int div=64) {  int nr= image.rows;//number of rows  int nc= image.cols * image.channels ();//total number of elements per line  if (image.iscontinuous ())  {  //Then no padded pixels  nc= nc*nr;   Nr= 1;  It is now a 1D array  }  int n= static_cast<int> (log (static_cast<double> (div))/log (2.0));  Mask used to round the pixel value  uchar mask= 0xff<<n;//e.g. for div=16, mask= 0xF0 for  (int j=0; j& LT;NR; J + +) {  uchar* data= image.ptr<uchar> (j);  for (int i=0; i<nc; i++) {  *data++= *data&mask + div/2;  }//End of Row                   }  }  int main (int a rgc,char* argv[]) {Cv::mat pimg;pimg=cv::imread ("lena.jpg"); Cv::imshow ("Image", pImg); Colorreduce (PIMG); cv::imshow ("PIMG", pImg); Cv::waitkey (0); return 0;}

Mat::reshape
Change the shape and number of channels or one of the 2D matrices without duplicating data.
C + +: Mat mat::reshape (int cn, int rows=0) const
Parameters:
CN-Keying the number of new channels. If cn=0, then the number of channels will remain unchanged.
rows– the new number of rows. If rows = 0, then the number of rows remains the same.

if (image.iscontinuous ()) {image.reshape (1,image.cols*image.rows);} int nr= image.rows; Number of rows  int nc= image.cols * image.channels ();//total number of elements per line  

The same effect as above!

Opencv.2.computer.vision.application.programming.cookbook--efficient scanning of continuous images