<?php
$url = 'http://url/to/site';
$data = array(
  "tk" => $_GET["tk"]
);
$ch = curl_init($url);
//seteamos la petición
curl_setopt($ch, CURLOPT_POST, 1);
curl_setopt($ch, CURLOPT_POSTFIELDS, $data);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_FAILONERROR, true);
$response = curl_exec($ch);
if (curl_errno($ch)) {
  $response = curl_error($ch);
}
curl_close($ch);
echo $response;

$bs = new lecRed; //lecRed it's a class I created and used before
$tk = $_POST["tk"];
$rspta = $bs->searchByTK($tk)->fetchObject();//here I retrieve the info from the DB
$arr = array(
  "id"      => $rspta->ide,
  "name"  => $rspta->name,
  "adsc"  => $rspta->adsc,
  "pic" => $rspta->pic
);
echo "<h1>ID: " . $arr["id"] . "</h1>";
echo "<h1>NAME: " . $arr["name"] . "</h1>";
echo "<h1>ADSC: " . $arr["adsc"] . "</h1>";

echo "<img src='".$arr["pic"]."' />";

$file = 'img/' . $arr["pic"];
$type = 'image/jpeg';
header('Content-Type:' . $type);
header('Content-Length: ' . filesize($file));
readfile($file);

$file = 'img/' . $arr["pic"];
if (file_exists($file)) {
  header('Content-Description: File Transfer');
  header('Content-Type: application/octet-stream');
  header('Content-Disposition: attachment; filename=' . basename($file));
  header('Content-Transfer-Encoding: binary');
  header('Expires: 0');
  header('Cache-Control: must-revalidate, post-check=0, pre-check=0');
  header('Pragma: public');
  header('Content-Length: ' . filesize($file));
  ob_clean();
  flush();
  readfile($file);
  exit;
}

header('content-type: image/jpeg');
$image_file_path = "img/" . $arr["pic"];
switch (pathinfo($image_file_path)['extension']) {
  case 'png':
    $image = imagecreatefrompng($image_file_path);
    break;
  case 'gif':
    $image = imagecreatefromgif($image_file_path);
    break;
  default:
    $image = imagecreatefromjpeg($image_file_path);
}
echo imagejpeg($image);
imagedestroy($image);