Hướng dẫn dùng application/octet-stream image trong PHP

My application is having images sent to it from mobile devices with the content-type "application/octet-stream".

I need to process these images using the GD library, which means I need to be able to create an image object from the data.

Typically, I have been using imagecreatefromjpeg, imagecreatefrompng, imagecreatefromgif, etc, to handle files uploaded from web forms, but these don't seem to work when coming to me as application/octet-stream.

Any ideas on how I can achieve my goal?

EDIT

Here is the code I use to create the image identifier...my handler works perfectly throughout my site, the only difference I can tell between my site and the data from the iOS is the content-type

public function open_image($path) {
        # JPEG:
        $im = @imagecreatefromjpeg($path);
        if ($im !== false) { $this->image = $im; return $im; }

        # GIF:
        $im = @imagecreatefromgif($path);
        if ($im !== false) { $this->image = $im; return $im; }

        # PNG:
        $im = @imagecreatefrompng($path);
        if ($im !== false) { $this->image = $im; return $im; }

        $this->error_messages[] = "Please make sure the image is a jpeg, a png, or a gif.";
        return false;
    }