如何将图像读入文件？

I want my PHP script to load an image from a file system and pass it through an AJAX response to javascript which then loads the image into the browser using FileReader. I can't use image src for this because the file system is private and can't be accessed directly.

The only solution I have found is to use functions imagecreatefromjpg, imagecreatefrompng, etc. The problem with these functions is that they consume a lot more memory that the actual image size is. All I want is to pass the image as an ordinary file and let the javascript handle it.

EDIT:

I have some images stored in /private/images. Private folder blocks access through .htaccess. I basically send an AJAX request from /public/test.php to a handler, /public/handler.php, which should access /private/images and send back an image specified by a filename and an extension.

So far, I am testing with only a few images, so I just hardcode the name into the function call.

Use readfile and send appropriate headers for your file:

$fileMimeType = finfo_file(finfo_open(FILEINFO_MIME_TYPE), $filePath);
header("Content-Length: " . filesize($filePath));
header("Content-Type: " . $fileMimeType);
header("Content-Transfer-Encoding: binary");
header("Pragma: public");
readfile($filePath);