Sanity Check

jpg_encoder.cpp

#include <Magick++.h>
#include <fstream.h>
#include <math.h>
#include <sys/time.h>
#include <unistd.h>


using namespace Magick;
fstream fout;

class CImage
{
public:
  int maxX;
  int maxY;
  int cRes;
  int **intensity;

  void loadImage(char*);
  void compressImage(char*);
  
  CImage()
  {
    maxX = maxY = 0;
    intensity = NULL;
    cRes = 255;
  }

  void CImage::print()
  {
    for(int i=0;i<maxY;i++)
      {
	for(int j=0;j<maxX;j++)
	  cout<<" "<<intensity[i][j];
	cout<<"\n";
      }
  }
  
  ~CImage()
  {
    int i;
    for(i=0;i<maxY;i++)
      delete intensity[i];
    delete [] intensity;
  }
};


void CImage::loadImage(char* file)
{
  Image image(file);
  maxX=image.columns();
  maxY=image.rows();
  image.classType(DirectClass);
  Pixels view(image);
  PixelPacket *pixels=view.get(0,0,maxX,maxY);
  int i,j;
  intensity = new int*[maxY];
  for(int i=0;i<maxY;i++)
    intensity[i] = new int[maxX];
  for(i=0;i<maxY;i++)
    for(j=0;j<maxX;j++)
      {
	cout.flush();
        ColorGray gray=Color(*(pixels+i*maxX+j));
        intensity[i][j]=(int)(gray.shade()*cRes);
      }
}

float C(int u)
{
  if(u==0)
    return (1.0/sqrt(2.0));
  else
    return 1.0;
}

void DCT(int f[8][8],int F[8][8])
{
  float a;
  for(int u=0;u<8;u++)
    for(int v=0;v<8;v++)
      {
	a = 0.0;
	for(int x=0;x<8;x++)
	  for(int y=0;y<8;y++)
	    a += float(f[x][y])*cos((2.0*float(x)+1.0)*float(u)*3.14/16.0)*cos((2.0*float(y)+1.0)*float(v)*3.14/16.0);
	F[u][v] = int(0.25*C(u)*C(v)*a);
      }
}


void Quantize(int F[8][8], int QF[8][8])
{
  int q[8][8] = {16,11,10,16,24,40,51,61,
		 12,12,14,19,26,58,60,55,
		 14,13,16,24,40,57,69,56,
		 14,17,22,29,51,87,80,62,
		 18,22,37,56,68,109,103,77,
		 24,35,55,64,81,104,113,92,
		 49,64,78,87,103,121,120,101,
		 72,92,95,98,112,100,103,99 };
  int i,j;
  for(i=0;i<8;i++)
    for(j=0;j<8;j++)
      QF[i][j] = int(F[i][j]/q[i][j]);
}


void ZigZag(int QF[8][8],int ZZ[64])
{
  int i=0,j=0,k=0,d=0;
  while(k<36)
    {
      //      cout<<"["<<i<<","<<j<<"]";
      ZZ[k++] = QF[i][j];
      if((i==0)&&(j%2==0))
	{
	  j++;
	  d=1;
	}
      else if((j==0)&&(i%2==1))
	{
	  i++;
	  d=0;
	}
      else if(d==0)
	{
	  i--;
	  j++;
	}
      else
	{
	  i++;
	  j--;
	}
    }
  i = 7;
  j = 1;
  d = 0;
  while(k<64)
    {
      //      cout<<"["<<i<<","<<j<<"]";
      ZZ[k++] = QF[i][j];
      if((i==7)&&(j%2==0))
	{
	  j++;
	  d=0;
	}
      else if((j==7)&&(i%2==1))
	{
	  i++;
	  d=1;
	}
      else if(d==0)
	{
	  i--;
	  j++;
	}
      else
	{
	  i++;
	  j--;
	}
    }
}

int RLE(int ZZ[64],int RL[64])
{
  int rl=1;
  int i=1;
  int k = 0;
  RL[0] = ZZ[0];
  while(i<64)
    {
      k=0;
      while((i<64)&&(ZZ[i]==0)&&(k<15))
	{
	  i++;
	  k++;
	}
      if(i==64)
	{
	  RL[rl++] = 0;
	  RL[rl++] = 0;
	}
      else
	{ 
	  RL[rl++] = k;
	  RL[rl++] = ZZ[i++];
	}
    }
  if(!(RL[rl-1]==0 && RL[rl-2]==0))
    {
      RL[rl++] = 0;
      RL[rl++] = 0;
    }
  if((RL[rl-4]==15)&&(RL[rl-3]==0))
    {
      RL[rl-4]=0;
      rl-=2;
    }
  return rl;
}


void writeToFile(char* a)
{
int len = strlen(a);
 int b = 0;
 int c = len/8;
 int i,j;
 //cout<<"c : "<<c;
 char d;
 for(i=0;i<=c;i++)
 {
   b = 0;
   for(j=0;j<8;j++)
      if((i*8+j<len)&&(a[i*8+j]=='1'))
	b = b | (int)pow(2,7-j);
   d = b;
   fout<<d;
   //   cout<<b<<" ";
 }
}

int getCat(int a)
{
  if(a==0)
	return 0;
  else if(abs(a)<=1)
	return 1;
  else if(abs(a)<=3)
	return 2;
  else if(abs(a)<=7)
	return 3;
  else if(abs(a)<=15)
	return 4;
  else if(abs(a)<=31)
	return 5;
  else if(abs(a)<=63)
	return 6;
  else if(abs(a)<=127)
	return 7;
  else if(abs(a)<=255)
	return 8;
  else if(abs(a)<=511)
	return 9;
  else if(abs(a)<=1023)
	return 10;
  else if(abs(a)<=2047)
	return 11;
  else if(abs(a)<=4095)
	return 12;
  else if(abs(a)<=8191)
	return 13;
  else if(abs(a)<=16383)
	return 14;
  else
	return 15;
}

void getDCcode(int a,int& lenb,char *b)
{
  int codeLen[12] = {3,4,5,5,7,8,10,12,14,16,18,20};
  char* code[12] = {"010","011","100","00","101","110","1110","11110","111110","1111110","11111110","111111110"};
  int cat = getCat(a);
  lenb = codeLen[cat];
  strcpy(b,code[cat]);
  int j;
  int c = a;
  if(a<0)
     c+=(int)pow(2,cat)-1;
  for(j=lenb-1;j>lenb-cat-1;j--)
  {
     if(c%2==1)
	b[j] = '1';
     else
	b[j] = '0';
     c/=2;
  }
  b[lenb] = '\0';
}

void getACcode(int n,int a, int& lenb, char* b)
{
  int codeLen[16][11] = {
  4 ,3 ,4 ,6 ,8 ,10,12,14,18,25,26,
  0 ,5 ,8 ,10,13,16,22,23,24,25,26,
  0 ,6 ,10,13,20,21,22,23,24,25,26,
  0 ,7 ,11,14,20,21,22,23,24,25,26,
  0 ,7 ,12,19,20,21,22,23,24,25,26,
  0 ,8 ,12,19,20,21,22,23,24,25,26,
  0 ,8 ,13,19,20,21,22,23,24,25,26,
  0 ,9 ,13,19,20,21,22,23,24,25,26,
  0 ,9 ,17,19,20,21,22,23,24,25,26,
  0 ,10,18,19,20,21,22,23,24,25,26,
  0 ,10,18,19,20,21,22,23,24,25,26,
  0 ,10,18,19,20,21,22,23,24,25,26,
  0 ,11,18,19,20,21,22,23,24,25,26,
  0 ,12,18,19,20,21,22,23,24,25,26,
  0 ,13,18,19,20,21,22,23,24,25,26,
  12,17,18,19,20,21,22,23,24,25,26
  };
  char* code[16][11] = {
  "1010",  "00",  "01",  "100",  "1011",  "11010",  "111000",  "1111000",  "1111110110",  "1111111110000010",  "1111111110000011",
  "","1100","111001","1111001","111110110","11111110110","1111111110000100","1111111110000101","1111111110000110","1111111110000111","1111111110001000",
  "","11011","11111000","1111110111","1111111110001001","1111111110001010","1111111110001011","1111111110001100","1111111110001101","1111111110001110","1111111110001111",
  "","111010","111110111","11111110111","1111111110010000","1111111110010001","1111111110010010","1111111110010011","1111111110010100","1111111110010101","1111111110010110",
  "","111011","1111111000","1111111110010111","1111111110011000","1111111110011001","1111111110011010","1111111110011011","1111111110011100","1111111110011101","1111111110011110",
  "","1111010","1111111001","1111111110011111","1111111110100000","1111111110100001","1111111110100010","1111111110100011","1111111110100100","1111111110100101","1111111110100110",
  "","1111011","11111111000","1111111110100111","1111111110101000","1111111110101001","1111111110101010","1111111110101011","1111111110101100","1111111110101101","1111111110101110",
  "","11111001","11111111001","1111111110101111","1111111110110000","1111111110110001","1111111110110010","1111111110110011","1111111110110100","1111111110110101","1111111110110110",
  "","11111010","111111111000000","1111111110110111","1111111110111000","1111111110111001","1111111110111010","1111111110111011","1111111110111100","1111111110111101","1111111110111110",
  "","111111000","1111111110111111","1111111111000000","1111111111000001","1111111111000010","1111111111000011","1111111111000100","1111111111000101","1111111111000110","1111111111000111",
  "","111111001","1111111111001000","1111111111001001","1111111111001010","1111111111001011","1111111111001100","1111111111001101","1111111111001110","1111111111001111","1111111111010000",
  "","111111010","1111111111010001","1111111111010010","1111111111010011","1111111111010100","1111111111010101","1111111111010110","1111111111010111","1111111111011000","1111111111011001",
  "","1111111010","1111111111011010","1111111111011011","1111111111011100","1111111111011101","1111111111011110","1111111111011111","1111111111100000","1111111111100001","1111111111100010",
  "","11111111010","1111111111100011","1111111111100100","1111111111100101","1111111111100110","1111111111100111","1111111111101000", "1111111111101001","1111111111101010","1111111111101011",
  "","111111110110","1111111111101100","1111111111101101","1111111111101110","1111111111101111","1111111111110000","1111111111110001","1111111111110010","1111111111110011","1111111111110100",
  "111111110111","1111111111110101","1111111111110110","1111111111110111","1111111111111000","1111111111111001","1111111111111010","1111111111111011","1111111111111100","1111111111111101","1111111111111110"
  };

  int cat = getCat(a);
  lenb = codeLen[n][cat];
  strcpy(b,code[n][cat]);
  int j;
  int c = a;
  if(a<0)
     c+=(int)pow(2,cat)-1;
  for(j=lenb-1;j>lenb-cat-1;j--)
  {
     if(c%2==1)
	b[j] = '1';
     else
	b[j] = '0';
     c/=2;
  }
  b[lenb] = '\0';
}

void Encode(int RL[64], int rl, char* output)
{
//   char output[33*26];
   char b[32];
   int bLen;
   getDCcode(RL[0],bLen,b);
   //   cout<<"Code : "<<RL[0]<<" "<<b;
   strcpy(output,b);
   int i;
   for(i=1;i<rl;i+=2)
   {
	getACcode(RL[i],RL[i+1],bLen,b);
	//	cout<<" , "<<RL[i]<<" "<<RL[i+1]<<" "<<b;
	strcat(output,b);
   }
//   writeToFile(output);
}

void prn(int a[8][8])
{
  for(int i=0;i<8;i++,cout<<"\n")
    for(int j=0;j<8;j++)
      cout<<a[i][j]<<" ";
}

int Compress(int f[8][8],int DCcomp, char* code)
{
  int F[8][8];
  // cout<<"f : \n";prn(f);
  DCT(f,F); 
  // cout<<"DCT : \n";prn(F);
  int QF[8][8];
  Quantize(F,QF);
  
  //cout<<"QF : \n";prn(QF);

  int newDC = QF[0][0];
  QF[0][0] -= DCcomp;

  int ZZ[64];
  ZigZag(QF,ZZ);
  
  int RL[64];
  int rl;
  rl = RLE(ZZ,RL);

  Encode(RL,rl,code);

  return newDC;
}

void CImage::compressImage(char* fname)
{
  fout.open(fname,ios::out);
  int i,j,i1,j1;
  int f[8][8];
  int DCcomp = 0;
  char code[1000];
  char writecode[80*80*26*32]; 
  writecode[0] = '\0';
  char x = ((maxX+7)/8);
  char y = ((maxY+7)/8);
  fout<<x<<y;
  cout<<"\nNumber of Blocks : "<<(int)y<<"*"<<(int)x<<"\n";
  for(i=0;i<maxY/8;i++)
    for(j=0;j<maxX/8;j++)
    {	
	for(i1=0;i1<8;i1++)
	  for(j1=0;j1<8;j1++)
	    if((i*8+i1<maxY)&&(j*8+j1<maxX))
	      f[i1][j1] = intensity[i*8+i1][j*8+j1]-128;
	    else
	      f[i1][j1] = 0;
	cout<<"\nProcessing Block : "<<i<<"*"<<j;
	DCcomp = Compress(f,DCcomp,code);
	strcat(writecode,code);
	//	int a;
	//cout<<"a : ";cin>>a;
    }  
  char *end = "111111111";
  strcat(writecode,end);
  writeToFile(writecode);
  fout.close();
}

void main()
{
  CImage i;
  char fname[20];
  cout<<"\n\nEnter name of image file (GIF file) : ";
  cin>>fname;
  i.loadImage(fname);
  // i.print();
  cout<<"\n\nImage is loaded.\nSize is : "<<i.maxY<<"X"<<i.maxX<<"\n";
  cout<<"Enter output file name : ";
  cin>>fname;
  strcat(fname,".Ajpg");
  i.compressImage(fname);
}