note 86858 added to function.imagejpeg

I came here looking for something similar to the getJPEGresolution function, but noticed the drawbacks that were pointed out in the last post. So, after drawing on some other code examples on the web, I put together the following function which should always properly return the correct values. (But remember that you still need to have the EXIF extension installed with your instance of PHP for this to work!) <?php function jpeg_dpi($filename) { if ( exif_imagetype($filename) != IMAGETYPE_JPEG ) { return false; } else { $exif = exif_read_data($filename, 'IFD0'); } $x = $y = 0; if ( isset($exif['XResolution']) && isset($exif['YResolution']) ) { $x = intval(preg_replace('@^(\\d+)/(\\d+)$@e', '$1/$2', $exif['XResolution'])); $y = intval(preg_replace('@^(\\d+)/(\\d+)$@e', '$1/$2', $exif['YResolution'])); } if ( !$x && !$y && $fp = fopen($filename, 'r') ) { $string = fread($fp, 20); fclose($fp); $data = bin2hex(substr($string, 14, 4)); $x = hexdec(substr($data, 0, 4)); $y = hexdec(substr($data, 4, 4)); } if ( $x || $y ) { return array($x, $y); } return false; } ?> This function returns an array with the x-resolution, y-resolution when they can be determined, otherwise FALSE. ---- Server IP: 209.41.74.194 Probable Submitter: 66.170.4.122 ---- Manual Page -- http://www.php.net/manual/en/function.imagejpeg.php Edit -- https://master.php.net/note/edit/86858 Del: integrated -- https://master.php.net/note/delete/86858/integrated Del: useless -- https://master.php.net/note/delete/86858/useless Del: bad code -- https://master.php.net/note/delete/86858/bad+code Del: spam -- https://master.php.net/note/delete/86858/spam Del: non-english -- https://master.php.net/note/delete/86858/non-english Del: in docs -- https://master.php.net/note/delete/86858/in+docs Del: other reasons-- https://master.php.net/note/delete/86858 Reject -- https://master.php.net/note/reject/86858 Search -- https://master.php.net/manage/user-notes.php