long Color1,Bcolor1,Gcolor1,Rcolor1;
long Color2,Bcolor2,Gcolor2,Rcolor2;
DoubleBuffer1->Assign(Image1->Picture->Bitmap);
DoubleBuffer2->Assign(Image2->Picture->Bitmap);    for(int y=0;yHeight;y  )
{
  for(int x=0;xWidth;x  )
  {
    Color1=DoubleBuffer1->Canvas->Pixels[x][y];
    Bcolor1=Color1/65536;
    Gcolor1=(Color1-Bcolor1*65536)/256;
    Rcolor1=(Color1-Bcolor1*65536-Gcolor1*256);        Bcolor1=(Bcolor1 Gcolor1 Rcolor1)/3 ;
    Gcolor1=Bcolor1;
    Rcolor1=Bcolor1;
    DoubleBuffer1->Canvas->Pixels[x][y]=  Rcolor1 Gcolor1*256 Bcolor1*65536; //Image1變灰階圖片
    }
  }      for(int y=0;yHeight;y  )
  {
    for(int x=0;xWidth;x  )
    {
      Color2=DoubleBuffer2->Canvas->Pixels[x][y];
      Bcolor2=Color2/65536;
      Gcolor2=(Color2-Bcolor2*65536)/256;
      Rcolor2=(Color2-Bcolor2*65536-Gcolor2*256);          Bcolor2=(Bcolor2 Gcolor2 Rcolor2)/3 ;
      Gcolor2=Bcolor2;
      Rcolor2=Bcolor2;
      DoubleBuffer2->Canvas->Pixels[x][y]= Rcolor2 Gcolor2*256 Bcolor2*65536; //Image2變灰階圖片
    }
  }      //===相減===
  long R,G,B;
  long GrayColor1,GrayColor2;
  for(int y=0;yPicture->Height;y  )
  {
    for(int x=0;xPicture->Width;x  )
    {
      GrayColor1=DoubleBuffer1->Canvas->Pixels[x][y];
      GrayColor2=DoubleBuffer2->Canvas->Pixels[x][y];
      R=abs(GetRValue(GrayColor1)-GetRValue(GrayColor2));
      G=abs(GetGValue(GrayColor1)-GetGValue(GrayColor2));
      B=abs(GetBValue(GrayColor1)-GetBValue(GrayColor2));
      DoubleBuffer3->Canvas->Pixels[x][y]= R G*256 B*65536;
    }
  }
  Image3->Picture->Bitmap->Assign(DoubleBuffer3);
  //==========