php imagepng无法正常工作。 显示问号

Question

I have following problem: imagepng, imagejpeg not working. I Got black question marks(unknown character list) on white screen. gd2 module is on. for example take this simple code:

$im = imagecreatefrompng($file_name);

header('Content-Type: image/png');

imagepng($im);
imagedestroy($im)

what i am missing?

Answer 1

This worked for me

$im = imagecreatefrompng("1.png");
ob_clean();
header('Content-Type: image/png');
imagepng($im);
imagedestroy($im);