Đặng Phương Nam

PHP function simply get image DPI in PHP without Imagick or GD library

Use this PHP function to get resolution (image dpi).
function get_dpi($filename){
    $a = fopen($filename,'r');
    $string = fread($a,20);
    fclose($a);

    $data = bin2hex(substr($string,14,4));
    $x = substr($data,0,4);
    $y = substr($data,4,4);

    return array(hexdec($x),hexdec($y));
}
Just call
get_dpi("image.jpg");
That's all thing we need to do.