如何使用 PHP 读取图像？
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How to read an image with PHP?
提问by Michael Berkowski
i know that
我知道
$localfile = $_FILES['media']['tmp_name'];
will get the image given that the POST method was used. I am trying to read an image which is in the same directory as my code. How do i read it and assign it to a variable like the one above?
鉴于使用了 POST 方法，将获得图像。我正在尝试读取与我的代码位于同一目录中的图像。我如何阅读它并将其分配给像上面那样的变量？
回答by Michael Berkowski
The code you posted will not read the image data, but rather its filename. If you need to retrieve an image in the same directory, you can retrieve its contents with file_get_contents(), which can be used to directly output it to the browser:
您发布的代码不会读取图像数据，而是读取其文件名。如果需要检索同目录下的图片，可以使用 检索其内容file_get_contents()，可以直接输出到浏览器：
$im = file_get_contents("./image.jpeg");
header("Content-type: image/jpeg");
echo $im;
Otherwise, you can use the GD libraryto read in the image data for further image processing:
否则，您可以使用GD 库读取图像数据以进行进一步的图像处理：
$im = imagecreatefromjpeg("./image.jpeg");
if ($im) {
// do other stuff...
// Output the result
header("Content-type: image/jpeg");
imagejpeg($im);
}
Finally, if you don't knowthe filename of the image you need (though if it's in the same location as your code, you should), you can use a glob()to find all the jpegs, for example:
最后，如果您不知道所需图像的文件名（尽管如果它与您的代码位于同一位置，您应该知道），您可以使用 aglob()来查找所有 jpeg，例如：
$jpegs = glob("./*.jpg");
foreach ($jpegs as $jpg) {
// print the filename
echo $jpg;
}
回答by Raj Sharma
If you want to read an image and then render it as an image
如果要读取图像然后将其渲染为图像
$image="path-to-your-image"; //this can also be a url
$filename = basename($image);
$file_extension = strtolower(substr(strrchr($filename,"."),1));
switch( $file_extension ) {
case "gif": $ctype="image/gif"; break;
case "png": $ctype="image/png"; break;
case "jpeg":
case "jpg": $ctype="image/jpeg"; break;
default:
}
header('Content-type: ' . $ctype);
$image = file_get_contents($image);
echo $image;
If your path is a url, and it is using https:// protocol then you might want to change the protocol to http
如果您的路径是一个 url，并且它使用的是 https:// 协议，那么您可能希望将协议更改为 http
