How can I strip the data:image part from a base64 string of any image type in PHP

Question

I am currently doing the following to decode base64 images in PHP:

   $img = str_replace('data:image/jpeg;base64,', '', $s['image']);
   $img = str_replace('data:image/png;base64,', '', $s['image']);
   $img = str_replace('data:image/gif;base64,', '', $s['image']);
   $img = str_replace('data:image/bmp;base64,', '', $s['image']);
   $img = str_replace(' ', '+', $img);
   $data = base64_decode($img);

As you can see above we are accepting the four most standard image types (jpeg, png, gif, bmp);

However, some of these images are very large and scanning through each one 4-5 times with str_replace seems a dreadful waste and terribly inefficient.

Is there a way I could reliably strip the data:image part of a base64 image string in a single pass? Perhaps by detecting the first comma in the string?

My apologies if this is a simple problem, PHP is not my forte. Thanks in advance.

score 33 · Accepted Answer · answered Mar 08 '13 at 09:58

33

You can use a regular expression:

$img = preg_replace('#data:image/[^;]+;base64,#', '', $s['image']);

if the text you are replacing is the first text in the image, adding ^ at the beginning of the regexp will make it much faster, because it won't analyze the entire image, just the first few characters:

$img = preg_replace('#^data:image/[^;]+;base64,#', '', $s['image']);

answered Mar 08 '13 at 09:58

Carlos Campderrós

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Perfect! Although all the answers are good and work perfectly. It appears that your method is the fastest, therefore I will award you with the answer as soon as I am able. Many thanks. :) – gordyr Mar 08 '13 at 10:02

score 25 · Answer 2 · edited Feb 09 '17 at 09:06

25

Function file_get_contents remove header and use base64_decode function, so you get clear content image.

Try this code:

$img = 'data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAA0gA...';
$imageContent = file_get_contents($img);

edited Feb 09 '17 at 09:06

Zameer Khan

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answered Jan 23 '14 at 07:59

sebob

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this should be the accepted answer. very smart solution! – raphael Aug 31 '15 at 11:27
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This should definitely be the accepted answer, a much more elegant solution – André Figueira Oct 25 '15 at 16:34
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I'm a bit late to the party, but this is by far the best answer. – shankie_san Jan 21 '19 at 18:03
Please try this, this is more straight forward! – Sobin Augustine Aug 11 '20 at 16:06
Isn't this opening up for security threats? – Anders Lindén May 16 '21 at 12:23
this is ultra smart. thanks – mending3 Oct 19 '22 at 06:57

score 0 · Answer 3 · answered Mar 08 '13 at 09:58

0

You would have to test it but I think this solution should be slightly faster than Mihai Iorga's

$offset = str_pos($s['image'], ',');
$data = base64_decode(substr($s['image'], $offset));

answered Mar 08 '13 at 09:58

TFennis

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Severin · Answer 4 · 2018-10-13T14:16:33.630

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I generete a image with javascript/kendo and send this by ajax to the server.

preg_replace('#^data:image/[^;]+;base64,#', '', $s['image']);

it does not work in this case. in my case this code works better:

$contentType  = mime_content_type($s['image']);
$img = preg_replace('#^data:image/(.*?);base64,#i', '$2', $s['image']);

edited Oct 13 '18 at 14:16

answered Oct 12 '18 at 15:38

Severin

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Can you add a bit of explanation on why this works better' – Marcello B. Oct 12 '18 at 15:55
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I generete a image with javascript/kendo and send this by ajax to the server. `preg_replace('#^data:image/[^;]+;base64,#', '', $s['image']);` it does not work in this case. – Severin Oct 12 '18 at 16:13
Perfect, please add that to your answer :) – Marcello B. Oct 12 '18 at 16:14

score 0 · Answer 5 · answered May 12 '20 at 09:05

0

You can Regular expression for remove image or pdf data formate.

data.replace(/^data:application\/[a-z]+;base64,/, "")

answered May 12 '20 at 09:05

Ankit Kumar Rajpoot

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How can I strip the data:image part from a base64 string of any image type in PHP

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