Como converte um arquivo jpeg em bmp

Function JpgToBmp(cImage: String): Boolean;
// Requer a Jpeg declarada na clausua uses da unit
var
MyJPEG : TJPEGImage;
MyBMP : TBitmap;
begin
Result := False;
if fileExists(cImage+'.Jpeg') then
begin
MyJPEG := TJPEGImage.Create;
with MyJPEG do
begin
try
LoadFromFile(cImage+'.Jpeg');
MyBMP := TBitmap.Create;
with MyBMP do
begin
Width := MyJPEG.Width;
Height := MyJPEG.Height;
Canvas.Draw(0,0,MyJPEG);
SaveToFile(cImage+'.Bmp');
Free;
Result := True;
end;
finally
Free;
end;
end;
end;
end;