生成任意阶的Bayer矩阵的程序

在Halftone图像处理方法中，高频振荡法是一种最快的方法，而Bayer法是高频振荡法里最简单的方法。

本文给出了一种Bayer矩阵的生成代码。

 

本文的代码对作者前面一篇16*16阶的Bayer程序http://blog.youkuaiyun.com/LaPizza/archive/2008/10/29/3173591.aspx  进了大量修改，以面向对象的方式描述了一个Bayer矩阵对象。

 

首先定义一个描述Bayer矩阵的类BayerMatrix，该类继承了方阵sqMatrix类。

方阵定义如下：

class sqMatrix
 {//This is a class of square matrix
 public:
      sqMatrix(int r);
      int getEle(int i, int j);//To get element at Line i, Row j
      int getRank();
protected:
      int rank;
      int *val;
 };

包含指向方阵元素的指针 val 和方阵的阶rank，为了方便在BayerMatrix中可以方便地使用数据域，将这些东东放在projected中。

各个函数如何定义，请参照文章后面所附的源代码。

 

从上面继承生成BayerMatrix

class BayerMatrix:public sqMatrix
 {
 public:
  BayerMatrix(int r);
  BayerMatrix();
  void Print(); 
 };
 主要是要重写构造函数。

 

重写的构造函数如下：

BayerMatrix::BayerMatrix(int r):sqMatrix(r)
 {
  if(!Powof2(r)) //estimate wheter the rank is a power of 2
  {
   cout << "rank should be a power of 2" <<endl;
   std::system("pause");
   exit(0);
  }
  val = (int*)malloc(sizeof(int)*r*r);
  

  *(val + rank*0 + 0) = 0;
  *(val + rank*0 + 1) = 2;
  *(val + rank*1 + 0) = 3;
  *(val + rank*1 + 1) = 1;

  int b;
  b = logl(rank) / logl(2);
  for(int k=1; k<b; k++)
  {
   for(int i=0; i<pow(2,k); i++)
   {
   for(int j=0; j<pow(2,k); j++)
    {
     *(val + rank*i + j) *= 4;
     *(val + rank*(i+ static_cast<int>(pow(2,k))) + j) = *(val + rank*i + j) + 3;
     *(val + rank*i + static_cast<int>((j+pow(2,k)))) = *(val + rank*i + j) + 2;
     *(val + rank*(i+static_cast<int>(pow(2,k))) + (j+static_cast<int>(pow(2,k)))) = *(val + rank*i + j) + 1;
    }
   }
  }
}

上述构造函数，利用了Bayer矩阵的生成函数算法，有兴趣的话，可以查看相关文献。

 

在测试程序中，设计了一个验证Bayer矩阵元素分布情况的函数：

bool checkBayer(LaP::BayerMatrix B)
{//To check whether the built Bayer matrix is corrected.
 int rank;
 rank = B.getRank();
 int min = 256;
 int max = -1;
 int current;
 int up = rank*rank;

 for(int i=0; i<up; i++)
 {
  current = B.getEle(static_cast<int>(i/rank), static_cast<int>(i%rank));
  if(current < min)
   min = current;
  if(current > max)
  {
   max = current;
  }
  for(int j=i+1; j<up; j++)
  {
   if(current == B.getEle(static_cast<int>(j/rank), static_cast<int>(j%rank)))
   {
    cout << "Error!! The Element["
     << static_cast<int>(i/rank) << "][" << static_cast<int>(i%rank)
     << "] is same to the Element["
     << static_cast<int>(j/rank)<< "][" << static_cast<int>(j%rank)
     << "]" << endl;
    return false;
   }
  }
 }
 cout << "the min is " << min << endl;
 cout << "the max is " << max << endl;
 cout << "all the elements are different/n";
 return true;
}

   

来判断Bayer矩阵中元素是否各异，并找出最大最小值。

 

 

 

 

详细代码如下：

bayer.h文件：

/**************************************************
* File:  bayer.h                               *
* Goal:  A declaration of Bayer                *
* Version: 1.1p                                  *
* Author: LaPizza (lapizza@163.com)             *
* Date:  Oct,2008                              *
**************************************************/
//

#ifndef BayerH
#define BayerH

#include <iostream>
#include "math.h"
using namespace std;

namespace LaP
{
 class sqMatrix
 {//This is a class of square matrix
 public:
  sqMatrix(int r);
  int getEle(int i, int j);//To get element at Line i, Row j
  int getRank();
 protected:
  int rank;
  int *val;
 };

 

 class BayerMatrix:public sqMatrix
 {
 public:
  BayerMatrix(int r);
  BayerMatrix();
  void Print(); 
 };
 

 //Check whether the input number @n is a power of 2
 bool Powof2(int n);
 
}

#endif

 

 

 

bayer.cpp文件：

/**************************************************
* File:  bayer.cpp                             *
* Goal:  A definition of Bayer                 *
* Version: 1.1p                                  *
* Author: LaPizza (lapizza@163.com)             *
* Date:  Oct,2008                              *
**************************************************/
//

#include <iostream>
#include "bayer.h"
#include "math.h"

bool LaP::Powof2(int n)
{
  int t = 1;
  for(int i=0; t < n ;i++)
   t *= 2;
  if(t == n)
   return true;
  else
   return false;
  
}

 void LaP::BayerMatrix::Print()
  {
   for(int i=0; i<rank; i++)
   {
    for(int j=0; j<rank; j++)
    {
     cout << //*(val + i*rank + j)
       getEle(i,j) << "/t";
    }
    cout << endl;
   }
  }

 

 

 LaP::sqMatrix::sqMatrix(int r)
 {
  val = (int*)malloc(sizeof(int)*r*r);
  rank = r;

 }

 int LaP::sqMatrix::getRank()
 {
  return rank;
 }

 int LaP::sqMatrix::getEle(int i, int j)
 {
  return *(val + i*getRank() + j);
 }

 LaP::BayerMatrix::BayerMatrix(int r):sqMatrix(r)
 {
  
  if(!Powof2(r))
  {
   cout << "rank should be a power of 2" <<endl;
   std::system("pause");
   exit(0);
  }
  val = (int*)malloc(sizeof(int)*r*r);
  

  *(val + rank*0 + 0) = 0;
  *(val + rank*0 + 1) = 2;
  *(val + rank*1 + 0) = 3;
  *(val + rank*1 + 1) = 1;

  int b;
  b = logl(rank) / logl(2);
  for(int k=1; k<b; k++)
  {
   for(int i=0; i<pow(2,k); i++)
   {
   for(int j=0; j<pow(2,k); j++)
    {
     *(val + rank*i + j) *= 4;
     *(val + rank*(i+ static_cast<int>(pow(2,k))) + j) = *(val + rank*i + j) + 3;
     *(val + rank*i + static_cast<int>((j+pow(2,k)))) = *(val + rank*i + j) + 2;
     *(val + rank*(i+static_cast<int>(pow(2,k))) + (j+static_cast<int>(pow(2,k)))) = *(val + rank*i + j) + 1;
    }
   }
  }  
}
   

 

 

测试文件 bMain.cpp:

/**************************************************
* Project: Bayer.sln (created by VS.net 2003)     *
*          To get a Bayer matrix for halftone     *
*                                                 *
* File:  bMain.cpp                             *
* Goal:  To test the class of BayerMatrix      *
* Version: 0.1T                                  *
* Author: LaPizza (lapizza@163.com)             *
* Date:  Oct,2008                              *
**************************************************/
//

#include <iostream>
using namespace std;

#include "bayer.h"

bool checkBayer(LaP::BayerMatrix B)
{//To check whether the built Bayer matrix is corrected.
 int rank;
 rank = B.getRank();
 int min = 256;
 int max = -1;
 int current;
 int up = rank*rank;

 for(int i=0; i<up; i++)
 {
  current = B.getEle(static_cast<int>(i/rank), static_cast<int>(i%rank));
  if(current < min)
   min = current;
  if(current > max)
  {
   
   max = current;
  }
  for(int j=i+1; j<up; j++)
  {
   if(current == B.getEle(static_cast<int>(j/rank), static_cast<int>(j%rank)))
   {
    cout << "Error!! The Element["
     << static_cast<int>(i/rank) << "][" << static_cast<int>(i%rank)
     << "] is same to the Element["
     << static_cast<int>(j/rank)<< "][" << static_cast<int>(j%rank)
     << "]" << endl;
    return false;
   }
   
  }
 }
 cout << "the min is " << min << endl;
 cout << "the max is " << max << endl;
 cout << "all the elements are different/n";
 return true;
}

int main()
{
 cout << "what is the rank of the matrix you want to build?/n >>";
 int ra;
 cin >> ra;
 LaP::BayerMatrix B(ra);
 B.Print();
 checkBayer(B);
 

 system("pause");
 return 0;
 
}