Сделать изображение более четким

Delphi , Графика и Игры , Изображения

Оформил: DeeCo
Автор: http://www.swissdelphicenter.ch

procedure Sharpen(sbm, tbm: TBitmap; alpha: Single);
 //to sharpen, alpha must be >1. 
//pixelformat pf24bit 
//sharpens sbm to tbm 
var
   i, j, k: integer;
   sr: array[0..2] of PByte;
   st: array[0..4] of pRGBTriple;
   tr: PByte;
   tt, p: pRGBTriple;
   beta: Single;
   inta, intb: integer;
   bmh, bmw: integer;
   re, gr, bl: integer;
   BytesPerScanline: integer;

 begin
   //sharpening is blending of the current pixel 
  //with the average of the surrounding ones, 
  //but with a negative weight for the average 
  Assert((sbm.Width > 2) and (sbm.Height > 2), 'Bitmap must be at least 3x3');
   Assert((alpha > 1) and (alpha < 6), 'Alpha must be >1 and <6');
   beta := (alpha - 1) / 5; //we assume alpha>1 and beta<1 
  intb := round(beta * $10000);
   inta := round(alpha * $10000); //integer scaled alpha and beta 
  sbm.PixelFormat := pf24bit;
   tbm.PixelFormat := pf24bit;
   tbm.Width := sbm.Width;
   tbm.Height := sbm.Height;
   bmw := sbm.Width - 2;
   bmh := sbm.Height - 2;
   BytesPerScanline := (((bmw + 2) * 24 + 31) and not 31) div 8;

   tr := tbm.Scanline[0];
   tt := pRGBTriple(tr);

   sr[0] := sbm.Scanline[0];
   st[0] := pRGBTriple(sr[0]);
   for j := 0 to bmw + 1 do
   begin
     tt^ := st[0]^;
     inc(tt); inc(st[0]); //first row unchanged 
  end;

   sr[1] := PByte(integer(sr[0]) - BytesPerScanline);
   sr[2] := PByte(integer(sr[1]) - BytesPerScanline);
   for i := 1 to bmh do
   begin
     Dec(tr, BytesPerScanline);
     tt := pRGBTriple(tr);
     st[0] := pRGBTriple(integer(sr[0]) + 3); //top 
    st[1] := pRGBTriple(sr[1]); //left 
    st[2] := pRGBTriple(integer(sr[1]) + 3); //center 
    st[3] := pRGBTriple(integer(sr[1]) + 6); //right 
    st[4] := pRGBTriple(integer(sr[2]) + 3); //bottom 
    tt^ := st[1]^; //1st col unchanged 
    for j := 1 to bmw do
     begin
     //calcutate average weighted by -beta 
      re := 0; gr := 0; bl := 0;
       for k := 0 to 4 do
       begin
         re := re + st[k]^.rgbtRed;
         gr := gr + st[k]^.rgbtGreen;
         bl := bl + st[k]^.rgbtBlue;
         inc(st[k]);
       end;
       re := (intb * re + $7FFF) shr 16;
       gr := (intb * gr + $7FFF) shr 16;
       bl := (intb * bl + $7FFF) shr 16;

     //add center pixel weighted by alpha 
      p := pRGBTriple(st[1]); //after inc, st[1] is at center 
      re := (inta * p^.rgbtRed + $7FFF) shr 16 - re;
       gr := (inta * p^.rgbtGreen + $7FFF) shr 16 - gr;
       bl := (inta * p^.rgbtBlue + $7FFF) shr 16 - bl;

     //clamp and move into target pixel 
      inc(tt);
       if re < 0 then
         re := 0
       else
         if re > 255 then
           re := 255;
       if gr < 0 then
         gr := 0
       else
         if gr > 255 then
           gr := 255;
       if bl < 0 then
         bl := 0
       else
         if bl > 255 then
           bl := 255;
       //this looks stupid, but avoids function calls 

      tt^.rgbtRed := re;
       tt^.rgbtGreen := gr;
       tt^.rgbtBlue := bl;
     end;
     inc(tt);
     inc(st[1]);
     tt^ := st[1]^; //Last col unchanged 
    sr[0] := sr[1];
     sr[1] := sr[2];
     Dec(sr[2], BytesPerScanline);
   end;
   // copy last row 
  Dec(tr, BytesPerScanline);
   tt := pRGBTriple(tr);
   st[1] := pRGBTriple(sr[1]);
   for j := 0 to bmw + 1 do
   begin
     tt^ := st[1]^;
     inc(tt); inc(st[1]);
   end;
 end;

Статья Сделать изображение более четким раздела Графика и Игры Изображения может быть полезна для разработчиков на Delphi и FreePascal.

Комментарии и вопросы

:: Главная :: Изображения ::