(PHP 5 >= 5.4.0, PHP 7)
getimagesizefromstring — Get the size of an image from a string
$imagedata
[, array &$imageinfo
] )Identical to getimagesize() except that getimagesizefromstring() accepts a string instead of a file name as the first parameter.
See the getimagesize() documentation for details on how this function works.
imagedataThe image data, as a string.
imageinfoSee getimagesize().
See getimagesize().
Example #1 getimagesizefromstring() example
<?php
$img = '/path/to/test.png';
// Open as a file
$size_info1 = getimagesize($img);
// Or open as a string
$data = file_get_contents($img);
$size_info2 = getimagesizefromstring($data);
?>
getimagesizefromstring function for < 5.4
<?php
if (!function_exists('getimagesizefromstring')) {
function getimagesizefromstring($string_data)
{
$uri = 'data://application/octet-stream;base64,' . base64_encode($string_data);
return getimagesize($uri);
}
}
?>
Just a quick comment on the solution by imageman for versions < 5.4 you will need to enable allow_url_fopen in order to use the data wrapper.
If you need to get the type (but not the size) of an image contained within a string, you can make use of the signatures contained within the headers of various file formats.
<?php
function get_img_type($data) {
$magics = array(
'ffd8ff' => 'jpg',
'89504e470d0a1a0a' => 'png',
);
foreach ($magics as $str => $ext) {
if (strtolower(bin2hex(substr($data, 0, strlen($str)/2))) == $str) return $ext;
}
return NULL;
}
?>
If required, additional magic signatures can be added to the array, there is a page on Wikipedia with a good list:
http://en.wikipedia.org/wiki/List_of_file_signatures
