php 从 base64 编码的 src 字符串中获取图像类型
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Get image type from base64 encoded src string
提问by Developer
WHAT I REQUIRE
我的要求
My image src looks like this
我的图像 src 看起来像这样
data:image/jpeg;base64,/9j/4AAQSkZJRgABAQAAAQABAA...
How can I extract the image type ie; jpegfrom the above src given. I am using PHP and the image type cacn also be png and gif.
如何提取图像类型，即；jpeg从上面给出的src。我正在使用 PHP，图像类型 cacn 也是 png 和 gif。
回答by Boris Guéry
Well you have basically two options:
那么你基本上有两个选择：
- Trust the metadata
- Type check the image source directly
- 信任元数据
- 直接打字查看图片来源
Option 1:
选项1：
Probably the quicker way because it only involve splitting string, but it may be incorrect. Something like:
可能是更快的方法，因为它只涉及拆分字符串，但它可能不正确。就像是：
$data = 'data:image/jpeg;base64,/9j/4AAQSkZJRgABAQAAAQABAA.';
$pos = strpos($data, ';');
$type = explode(':', substr($data, 0, $pos))[1];
Option 2:
选项 2：
Use getimagesize()and it's equivalent for string:
使用getimagesize()，它等效于字符串：
$info = getimagesizefromstring(explode(',', base64_decode($data)[1], 2));
// $info['mime']; contains the mimetype
回答by ComFreek
Test this:
测试这个：
<?php
$str = 'data:image/jpeg;base64,/9j/4AAQSkZJRgABAQAAAQABAA...';
function getB64Type($str) {
// $str should start with 'data:' (= 5 characters long!)
return substr($str, 5, strpos($str, ';')-5);
}
var_dump(getB64Type($str));
回答by Tiago Mendes
This is the way that i made:
这是我制作的方式：
$uri = "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAF......."
$img = explode(',', $uri);
$ini =substr($img[0], 11);
$type = explode(';', $ini);
echo $type[0]; // result png
回答by Juanes Rios
$encoded_string = "....";
$imgdata = base64_decode($encoded_string);
$f = finfo_open();
$mime_type = finfo_buffer($f, $imgdata, FILEINFO_MIME_TYPE);
回答by Matthew A Thomas
I hope this helps but the correct way to do this is.
我希望这会有所帮助，但正确的方法是。
$uri = "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAF......."
$encodedImgString = explode(',', $uri, 2)[1];
$decodedImgString = base64_decode($encodedImgString);
$info = getimagesizefromstring($decodedImgString);
echo $info['mime'];
Please don't just use the, data:image/pngas that is not reliable, I could easily fake that part and send you a base64 encoded .exe file.
请不要只使用data:image/png，因为它不可靠，我可以轻松伪造该部分并向您发送 base64 编码的 .exe 文件。
回答by imal hasaranga perera
You can use this, if you use ajax to upload images then you will not get the correct MIME using finfo_buffer
您可以使用它，如果您使用 ajax 上传图像，那么您将无法使用 finfo_buffer 获得正确的 MIME
function getMIMETYPE($base64string){
preg_match("/^data:(.*);base64/g",$base64string, $match);
echo $match[1];
}
回答by suman
Use below regex code, it returns the extension of a file.
使用下面的正则表达式代码，它返回文件的扩展名。
$base64string = 'data:image/jpeg;base64,/9j/4AAQSkZJRgABAQAAAQABAA...';
preg_match("/^data:image\/(.*);base64/i",$base64string, $match);
$extension = $match[1];
回答by Adam Pery
$str = 'data:image/jpeg;base64,/9j/4AAQSkZJRgABAQAAAQABAA...';
$ext = end(explode('/', (explode(';', $str))[0]));
Result: jpeg
结果：jpeg
回答by Keith Gulbro
This solution worked best for me, piggybacking off of Option 1 presented by Boris Guery.
这个解决方案对我来说效果最好，搭载了 Boris Guery 提出的选项 1。
$data = 'data:image/jpeg;base64,/9j/4AAQSkZJRgABAQAAAQABAA...';
$pos = strpos($data, ';');
$type = explode('/', substr($data, 0, $pos))[1];
In this instance the solution returns jpegfile extension, in the $typevariable.
在这种情况下，解决方案jpeg在$type变量中返回文件扩展名。
回答by Aymen Bouein
$str64 = base64 string
function base64Extension($str64) {
return explode(";", explode("/", $str64)[1])[0];
}
