function InvertBmp1(SourceBmp: TBitmap): TBitMap;
 var
 i, j: Longint;
 tmp: TBitMap;
 red, green, blue: Byte;
 PixelColor: Longint;
 begin
 tmp := TBitmap.Create;
 tmp.Width := SourceBmp.Width;
 tmp.Height := SourceBmp.Height;
 for i := 0 to SourceBmp.Width - 1 do
 begin
 for j := 0 to SourceBmp.Height - 1 do
 begin
 PixelColor := ColorToRGB(SourceBmp.Canvas.Pixels[i, j]);
 red := PixelColor;
 green := PixelColor shr 8;
 blue := PixelColor shr 16;
 red := 255 - red;
 green := 255 - green;
 blue := 255 - blue;
 tmp.Canvas.pixels[i, j] := (red shl 8 + green) shl 8 + blue;
 end;
 end;
 Result := tmp;
 end;

 function InvertBmp2(ABitmap : TBitmap) : TBitmap;
 var
 l_bmp : TBitmap;
 begin
 l_bmp := TBitmap.Create;
 l_bmp.Width := ABitmap.Width;
 l_bmp.Height := ABitmap.Height;
 l_bmp.PixelFormat := ABitmap.PixelFormat;
 BitBlt( l_bmp.Canvas.Handle, 0, 0, l_bmp.Width, l_bmp.Height,
 ABitmap.Canvas.Handle, 0, 0, SRCINVERT );
 result := l_bmp;
 end;