Storing image in database directly or as base64 data?

Question

The common method to store images in a database is to convert the image to base64 data before storing the data. This process will increase the size by 33%. Alternatively it is possible to directly store the image as a BLOB; for example:

$image = new Imagick("image.jpg");
$data = $image->getImageBlob();
$data = $mysqli->real_escape_string($data);
$mysqli->query("INSERT INTO images (data) VALUES ('$data')");

and then display the image with

<img src="data:image/jpeg;base64,' .  base64_encode($data)  . '" />

With the latter method, we save 1/3 storage space. Why is it more common to store images as base64 in MySQL databases?

UPDATE: There are many debates about advantages and disadvantages of storing images in databases, and most people believe it is not a practical approach. Anyway, here I assume we store image in database, and discussing the best method to do so.

Answer 1

I contend that images (files) are NOT usually stored in a database base64 encoded. Instead, they are stored in their raw binary form in a binary (blob) column (or file).

Base64 is only used as a transport mechanism, not for storage. For example, you can embed a base64 encoded image into an XML document or an email message.

Base64 is also stream friendly. You can encode and decode on the fly (without knowing the total size of the data).

While base64 is fine for transport, do not store your images base64 encoded.

Base64 provides no checksum or anything of any value for storage.

Base64 encoding increases the storage requirement by 33% over a raw binary format. It also increases the amount of data that must be read from persistent storage, which is still generally the largest bottleneck in computing. It's generally faster to read less bytes and encode them on the fly. Only if your system is CPU bound instead of IO bound, and you're regularly outputting the image in base64, then consider storing in base64.

Inline images (base64 encoded images embedded in HTML) are a bottleneck themselves--you're sending 33% more data over the wire, and doing it serially (the web browser has to wait on the inline images before it can finish downloading the page HTML).

If you still wish to store images base64 encoded, please, whatever you do, make sure you don't store base64 encoded data in a UTF8 column then index it.