Here is the code I did to create a thumbnail image from the database blob field. The trick is to use "imagecreatefromstring()" to create an image file.

Jack Shieh

<?php
require("dbconfig.inc");

$id = $_GET['id'];

if($id) {

    $link = @mysql_connect($host, $user, $password) or die("Could not connect: " . mysql_error());
    @mysql_select_db($dbname, $link);

    $query = "select filetype, image from pictures where id = $id";
    $result = @mysql_query($query);

    $data = @mysql_result($result,0,"image");
    $type = @mysql_result($result,0,"filetype");
    
    Header( "Content-type: $type");    
    
    $size = 150;  // new image width
    $src = imagecreatefromstring($data); 
    $width = imagesx($src);
    $height = imagesy($src);
    $aspect_ratio = $height/$width;

    if ($width <= $size) {
      $new_w = $width;
      $new_h = $height;
    } else {
      $new_w = $size;
      $new_h = abs($new_w * $aspect_ratio);
    }

    $img = imagecreatetruecolor($new_w,$new_h); 
    imagecopyresized($img,$src,0,0,0,0,$new_w,$new_h,$width,$height);
 
    // determine image type and send it to the client    
    if ($type == "image/pjpeg") {    
      imagejpeg($img); 
    } else if ($type == "image/x-png") {
      imagepng($img);
    } else if ($type == "image/gif") {
      imagegif($img);
    }
    imagedestroy($img); 
    mysql_close($link);
};
?>