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;