Create Image From Url Any File Type

The simplest way to do this is let php decide what is the file type:

$image = imagecreatefromstring(file_get_contents($src));

Maybe you want this:

$jpeg_image = imagecreatefromfile( 'photo.jpeg' );
$gif_image = imagecreatefromfile( 'clipart.gif' );
$png_image = imagecreatefromfile( 'transparent_checkerboard.PnG' );
$another_jpeg = imagecreatefromfile( 'picture.JPG' );
// This requires you to remove or rewrite file_exists check:
$jpeg_image = imagecreatefromfile( 'http://example.net/photo.jpeg' );
// SEE BELOW HO TO DO IT WHEN http:// ARGS IS NEEDED:
$jpeg_image = imagecreatefromfile( 'http://example.net/photo.jpeg?foo=hello&bar=world' );

Here's how it's done:

function imagecreatefromfile( $filename ) {
    if (!file_exists($filename)) {
        throw new InvalidArgumentException('File "'.$filename.'" not found.');
    }
    switch ( strtolower( pathinfo( $filename, PATHINFO_EXTENSION ))) {
        case 'jpeg':
        case 'jpg':
            return imagecreatefromjpeg($filename);
        break;

        case 'png':
            return imagecreatefrompng($filename);
        break;

        case 'gif':
            return imagecreatefromgif($filename);
        break;

        default:
            throw new InvalidArgumentException('File "'.$filename.'" is not valid jpg, png or gif image.');
        break;
    }
}

With some small modifications to switch same function is ready for web url's:

    /* if (!file_exists($filename)) {
        throw new InvalidArgumentException('File "'.$filename.'" not found.');
    } <== This needs addiotional checks if using non local picture */
    switch ( strtolower( array_pop( explode('.', substr($filename, 0, strpos($filename, '?'))))) ) {
        case 'jpeg':

After that you can use it with http://www.tld/image.jpg:

$jpeg_image = imagecreatefromfile( 'http://example.net/photo.jpeg' );
$gif_image = imagecreatefromfile( 'http://www.example.com/art.gif?param=23&another=yes' );

Some proofs:

As you can read from official PHP manual function.imagecreatefromjpeg.php GD allows loading images from URLs that is supported by function.fopen.php, so there is no need to fetch image first and save it to file, and open that file.

I use this function. It supports all types of urls and stream wrappers and all image types php can handle.

/**
 * creates a image ressource from file (or url)
 *
 * @version: 1.1 (2014-05-02)
 *
 * $param string:    $filename                    url or local path to image file
 * @param [bool:     $use_include_path]           As of PHP 5 the FILE_USE_INCLUDE_PATH constant can be used to trigger include path search.
 * @param [resource: $context]                    A valid context resource created with stream_context_create(). If you don't need to use a custom context, you can skip this parameter by NULL
 * @param [&array:   $info]                       Array with result info: $info["image"] = imageinformation from getimagesize, $info["http"] = http_response_headers (if array was populated)
 *
 * @see: http://php.net/manual/function.file-get-contents.php
 * @see: http://php.net/manual/function.getimagesize.php
 *
 * @return bool|resource<gd>                       false, wenn aus Dateiinhalt keine gueltige PHP-Bildresource erstellt werden konnte (z.b. bei BMP-Datei)
 * @throws InvalidArgumentException                Wenn Datei kein gueltiges Bild ist, oder nicht gelesen werden kann
 *
 */
function createImageFromFile($filename, $use_include_path = false, $context = null, &$info = null)
{
  // try to detect image informations -> info is false if image was not readable or is no php supported image format (a  check for "is_readable" or fileextension is no longer needed)
  $info = array("image"=>getimagesize($filename));
  $info["image"] = getimagesize($filename);
  if($info["image"] === false) throw new InvalidArgumentException("\"".$filename."\" is not readable or no php supported format");
  else
  {
    // fetches fileconten from url and creates an image ressource by string data
    // if file is not readable or not supportet by imagecreate FALSE will be returnes as $imageRes
    $imageRes = imagecreatefromstring(file_get_contents($filename, $use_include_path, $context));
    // export $http_response_header to have this info outside of this function
    if(isset($http_response_header)) $info["http"] = $http_response_header;
    return $imageRes;
  }
}

Usage (simple example):

$image = createImageFromFile("http://sample.com/image.png");

Usage (complex example):

// even sources with php extensions are supported and e.g. Proxy connections and other context Options
// see http://php.net/manual/function.stream-context-create.php for examples
$options = array("http"=> 
                  array("proxy" => "tcp://myproxy:8080",
                        "request_fulluri" => true
                       )
                  );
$context = stream_context_create($options);

$image = createImageFromFile("http://de3.php.net/images/logo.php", null, $context,$info);

// ... your code to resize or modify the image