PHP – resize images and helper image functions

Code:

 $widthdiff){
          $newwidth = ceil( $width*$newheight/$height);
       }else{
          $newheight = ceil( $height*$newwidth/$width);
       }
    }else if($newwidth < $width){
       $newheight = ceil( $height*$newwidth/$width);
    }else if($newheight < $height){
       $newwidth = ceil( $width*$newheight/$height);
    } else {
       $newwidth = $width;
       $newheight = $height;
    }
    $gd_version = gd_version();
    //$gd_version = 3;
    $thumb = null;
    if ($gd_version >= 2) {
        $thumb = imagecreatetruecolor($newwidth, $newheight);
    } else {
        $thumb = imagecreate($newwidth, $newheight);
    }
    // imagealphablending($thumb, false);
    // Resize
    //imagecopyresized($thumb, $image, 0, 0, 0, 0, $newwidth, $newheight, $width, $height);
    // Resample
    imagecopyresampled($thumb, $image, 0, 0, 0, 0, $newwidth, $newheight, $width, $height);
    return $thumb;
}

function image2jpeg($source, $destination, $type=null)
{
    if (!is_file($source)) {
       return false;
    }
    $image = null;
    // alternatively & better: get file extension and use it instead of preg_match
    if (preg_match("/.jpg$/i", $source) ||preg_match("/.jpeg$/i", $source) ||"jpg"==$type) { // mimeType: image/jpeg
        $image = imagecreatefromjpeg($source);
    } else if (preg_match("/.gif$/i", $source) || "gif"==$type) { // mimeType: image/gif
       $image = imagecreatefromgif($source);
    } else if (preg_match("/.png$/i", $source) || "png"==$type) { // mimeType: image/png
       $image = imagecreatefrompng($source);
    } else {
       return false; // unknown format
    }
    if (!$image) {
        return false;
    }
    mkpath(dirname($destination));
    imagejpeg($image, $destination);
    return true;
}

function webShowImage($source)
{
    Header("Content-type: image/jpeg");
    $im = imagecreatefromjpeg("$source");
    Imagejpeg($im, '', 100);
    ImageDestroy($im);
}

function webResizeImage($source, $newwidth, $newheight)
{
    $thumb = resize($source, $newwidth, $newheight);
    header('Content-type: image/jpeg');
    imagejpeg($thumb);
}

function gd_version() {
    static $gd_version_number = null;
    if ($gd_version_number === null) {
        // Use output buffering to get results from phpinfo()
        // without disturbing the page we're in.  Output
        // buffering is "stackable" so we don't even have to
        // worry about previous or encompassing buffering.
        ob_start();
        phpinfo(INFO_MODULES); // or 8
        $module_info = ob_get_contents();
        ob_end_clean();
        if (preg_match("/\bgd\s+version\b[^\d\n\r]+?([\d\.]+)/i",
               $module_info,$matches)) {
           $gd_version_number = $matches[1];
        } else {
           $gd_version_number = 0;
        }
    }
    return $gd_version_number;
}

?>