php 读文件

base64_encode(file_get_contents($path))

chunk_split($base64);　　//php - How to embed images in html email - Stack Overflow

base64_decode($base64); //Convert base64 to image file in PHP (netcell.netlify.app)

 

$file = '../image.jpg';
$type = 'image/jpeg';
header('Content-Type:'.$type);
header('Content-Length: ' . filesize($file));
readfile($file);

<?php
  header("Content-type: image/jpeg");
  readfile("/path/to/image.jpg");
  exit(0);
?>