restore base64_encode image to a file system from database - php

Question

I'm saving some of my image in to mysql database using base64_encode.
now I want to restore them back to file system.
How can I do that?
Edit...!
Ok, I did not explain enough.
I use this code to encode my image and save them in to a blob table:
function base64_encode_image ($imagefile) {
$imgtype = array('jpg', 'gif', 'png');
$filename = file_exists($imagefile) ? htmlentities($imagefile) : die('Image file name does not exist');
$filetype = pathinfo($filename, PATHINFO_EXTENSION);
if (in_array($filetype, $imgtype)){
$imgbinary = fread(fopen($filename, "r"), filesize($filename));
} else {
die ('Invalid image type, jpg, gif, and png is only allowed');
}
return 'data:image/' . $filetype . ';base64,' . base64_encode($imgbinary);
}
and use this code to show my image in browser:
if (!isset($_GET['id']) && !ctype_digit($_GET['id'])){
die('Error');
} else {
require_once( addslashes(dirname(dirname(__FILE__)) . '/config.php') );
require_once( addslashes(dirname(__FILE__) . '/Functions.php'));
$row = mysql_fetch_array(mysql_query ("SELECT `id`,`cover_small` FROM `om_manga` WHERE `Active` = '1' AND `id` = '".sql_quote($_GET['id'])."'"));
if (isset($row['id'])){
header("Content-type: image/jpeg");
readfile($row['cover_small']);
} else {
die('Error');
}
}
Now i want them back to a jpg file.
The size of all those image are less then 3kb.

Answer 1

Use PHP's base64_decode() function to convert the encoded data back to binary.
Since base64_decode returns a string, you can use file_put_contents() to write the decoded contents to a file.
It makes me wonder why you're storing the image base64 encoded if you're not using it in that format. You could just as easily store the image in binary format in a binary blob column.
Base64 encoding adds a 33% character overhead (not bytes).
Edit for revised question
The answer to your second question is subjective without context. Without knowing the details of your system, I can't recommend whether you should extract the images.

Answer 2

Decode it the same way you encoded it...
base64_decode()
You might want to store the file extension of the image when writing it to the database so that you can restore it accurately. Just concatenate the new name with the existing extension.
What you should so is something similar to this :
// Retrieved values from database
$encodedImg = $sqlResult['encoded_img'];
$ext = $sqlResult['encoded_img_ext'];
// Concatenate new file name with existing extention
// NOTE : This parameter is a full path. Make sure that the folder
// you are writing the file to has the correct permissions allowing the
// script write access.
$newImagePath = "/some/path/on/the/servers/filesystem/";
$newImageName = $newImagePath."decoded_image.".$ext;
// Saving the decoded file with the new file name.
file_put_contents($newImageName, base64_decode($encodedImg));