procedure EscribePixel(x,y : integer; r,g,b : byte; var b : TBitmap);
var
  Pix : PByteArray;
begin
  Pix := b.ScanLine[y];
  Pix[x*3]:=b;
  Pix[x*3+1]:=g;
  Pix[x*3+2]:=r;
end;

function CrearBitmap(tamx,tamy : integer) : TBitmap;
begin
  result:=TBitmap.Create;
  result.Height:=tamy;
  result.Width:=tamx;
  result.PixelFormat := pf24Bit;
end;