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.

Accepted Answer

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']);
```

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

Solution

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