» ini_set('memory_limit') je nach Auflösung, Farbtiefe, usw

// check image dimensions
$getimagesize = @getimagesize($src_file);
$width = $getimagesize[0];
$height = $getimagesize[1];
$bits = isset($getimagesize['bits']) ? $getimagesize['bits'] : 32;
$channels = isset($getimagesize['channels']) ? $getimagesize['channels'] : 8;
$K64 = pow(2,16); // number of bytes in 64K
$factor = 1.7;
// check orientation
$exif = exif_read_data($src_file);
$exif_orientation = isset($exif['Orientation']) ? $exif['Orientation'] : 0;
unset($exif);
$memory_twice = $exif_orientation > 1 && $exif_orientation < 9 ? 2 : 1;
$memory_needed = ($width * $height * $bits * $channels / 8 + $K64) * $factor * $memory_twice;
$memory_limit = intval(ini_get('memory_limit')) * pow(1024, 2); // if --disable-memorylimit is set this is 0
$memory_usage = function_exists('memory_get_usage') ? memory_get_usage() : 0;
$memory_new_limit = min(536870912, $memory_needed + $memory_usage);// do not set more than 512 MB
if ($memory_limit && $memory_new_limit > $memory_limit) {
	ini_set('memory_limit', ceil($memory_new_limit / pow(1024, 2)) . 'M')) {
}

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