get dpi of image in php

Hi to get the dpi of any image you can use the following code

php opening tag

function get_dpi($filename){

// open the file and read first 20 bytes.

$a = fopen($filename,’r');

$string = fread($a,20);

fclose($a);



// get the value of byte 14th up to 18th

$data = bin2hex(substr($string,14,4));

$x = substr($data,0,4);

$y = substr($data,4,4);

return array(hexdec($x),hexdec($y));

}

// sample, output the result:

print_r(get_dpi(‘demo_files/abc.png’));

php close tag