<?php
$filename = __DIR__ . '/_tmp.wbmp';
$fp = fopen($filename,"wb");
$c = 0;
fputs($fp, chr($c), 1);
fputs($fp, $c, 1);
$c = 0x84;
for ($i=0; $i<10000; $i++) {
fwrite($fp, chr($c), 1);
}
$im = imagecreatefromwbmp($filename);