Example:

$im = imageCreateFromPNG( "test-ob.png" );
ob_start();
imagePNG( $im );
$outbuffer = ob_get_contents();
ob_end_clean();
header( "Content-Type: image/gif" );
print $outbuffer;

(test url: "http://www.osd.dk/test/test-ob.php")

The script above will fail on the "header( ..." line stating that output has already been sent and thus no more headers can be added.

For some reason the imagePNG() function (and other image output functions) seems to end the header section of the output even though output buffering is active.

I'm currently unable to test this on a newer version of php.

Regards,
Tais M. Hansen