function ILimit(Val, AMin, AMax: Integer): Integer;
begin
 Result := Min(Max(Val, AMin), AMax);
end;

function BLimit(B: Integer): Byte;
begin
 if B < 0 then Result := 0
          else if B > 255 then Result := 255
                          else Result := B;
end;

procedure RadialBlur(SrcBmp, DestBmp: TBitmap; CX, CY, Size, Quality: Integer);
const Rad = Pi/180;
var x, y, i, i2, Red, Green, Blue, px, py, nx, ny: Integer;
   Dest: pByteArray;
   Src: array of pByteArray;
   ASin, ACos, Ang, A: Double;
begin
 SetLength(Src, SrcBmp.Height);
 i2 := Quality*Size;
 A := 1/Quality;
 for y := 0 to SrcBmp.Height - 1 do Src[y] := SrcBmp.ScanLine[y];
 for y := 0 to DestBmp.Height - 1 do begin
   Dest := DestBmp.ScanLine[y];
   for x := 0 to DestBmp.Width - 1 do begin
     Red   := -Dest[x*3];
     Green := -Dest[x*3+1];
     Blue  := -Dest[x*3+2];
     px := x - cx;
     py := y - cy;
     ASin := (Cy + y)/Hypot(Cx + x, Cy + y);
     Ang := ArcTan2(ASin, 1 - ASin*ASin) - Size div 2;
     for i := 0 to i2 do begin
       SinCos(Ang*Rad, ASin, ACos);
       nx := ILimit(CX + Round(px*ACos - py*ASin), 0, SrcBmp.Width - 1)*3;
       ny := ILimit(CY + Round(px*ASin + py*ACos), 0, SrcBmp.Height - 1);
       Inc(Red,   Src[ny][nx]);
       Inc(Green, Src[ny][nx+1]);
       Inc(Blue,  Src[ny][nx+2]);
       Ang := Ang + A;
     end;
     Dest[x*3]   := BLimit(Red   div i2);
     Dest[x*3+1] := BLimit(Green div i2);
     Dest[x*3+2] := BLimit(Blue  div i2);
   end;
 end;
end;