public function testConvert()
{
$i = new Gd(__DIR__ . '/../tmp/test.gif');
$i->convert('png');
$this->assertEquals(640, $i->getWidth());
$i = new Gd(__DIR__ . '/../tmp/test.png');
$i->convert('gif');
$this->assertEquals(640, $i->getWidth());
$i = new Gd(__DIR__ . '/../tmp/test.jpg');
$i->convert('png');
$this->assertEquals(640, $i->getWidth());
}