PHP - imagepng not working properly

Question

Well guys, first, here is my code:

<?php

ob_start();

$pilot_id = $_GET['id'];

//-- Server Variables
$dbServer        = 'localhost';
$dbUser          = 'root';
$dbPassword      = '*************';
$dbName          = 'bla_tracker';

//-- Server Connection >>> DO NOT CHANGE <<<
$sql = mysql_connect("$dbServer", "$dbUser", "$dbPassword") or die(mysql_error());
$select_db = mysql_select_db("$dbName", $sql);

$query = mysql_query("SELECT * FROM acars_users WHERE `id`='".$pilot_id."' ") or die (mysql_error());
$row = mysql_fetch_array($query);
$nome = $row['nome'];
$patente = $row['rank'];
$admin = $row['admin'];
$checador = $row['checador'];

$query_horas = mysql_query("SELECT SUM(flighttime) AS `total` FROM acars_pirep WHERE iduser='".$pilot_id."'") or die (mysql_error());
$row2 = mysql_fetch_assoc($query_horas);
$total_min = $row2['total'] + ($row['horas'] * 60);
$total = round($total_min/60);

  if($admin == 1) {
     $data = "Comandante Master - $nome";
  } else {
  if($checador == 1) {
     $data = "Comandante Checador - $nome";  
  } else {
  if($patente == '4') {
     $data = "Comandante Sênior - $nome";   
  } else {
  if($patente == '3') {
     $data = "Comandante Instrutor - $nome"; 
  } else {
  if($patente == '2') {
     $data = "Comandante - $nome"; 
  } else {
  if($patente == '1') {
     $data = "Primeiro Oficial - $nome"; 
  } else {
  if($patente == '0') {
     $data = "Copiloto - $nome";     
  }}}}}}}


$rand = rand(1, 8);

$my_img = imagecreatefrompng("images/background_$rand.png");
$background = imagecolorallocate($my_img, 0, 0, 255);
$text_colour = imagecolorallocate($my_img, 255, 255, 255);


imagettftext($my_img, 11, 0, 4, 12, $text_colour, "calibril.ttf", "$data");
imagettftext($my_img, 11, 0, 340, 12, $text_colour, "calibril.ttf", "$total hrs");
imagettftext($my_img, 11, 0, 4, 98, $text_colour, "calibril.ttf", "Brasil Linhas Aéreas");
imagettftext($my_img, 11, 0, 323, 98, $text_colour, "calibril.ttf", "voebla.com");

imagesetthickness ($my_img, 5 );


header("Content-type: image/png");
imagepng($my_img);
imagecolordeallocate( $text_color );
imagecolordeallocate( $background );
imagedestroy($my_img);

?>

We changed the servers, and now, I get this:

enter image description here

What is happening?

EDIT

Setting PHP errors to ON, I get this warning:

Warning: Cannot modify header information - headers already sent by (output started at C:\Inetpub\vhosts\voebla.com\httpdocs\BLAtracker\sessoes\pilotos\modules\dados\assinatura\assinatura.php:1) in C:\Inetpub\vhosts\voebla.com\httpdocs\BLAtracker\sessoes\pilotos\modules\dados\assinatura\assinatura.php on line 68

And in line 68 we have:

header( "Content-type: image/png" );

EDIT 2

Taking a deeper look into assinatura.php, I've found out a BOM before the PHP tag, but now how to remove it?

enter image description here

This link may be helpful. http://stackoverflow.com/questions/64860/best-way-to-convert-text-files-between-character-sets — Richard, Apr 24 '14 at 01:13
According to the docs, [`imagecreatefrompng()`](http://www.php.net/manual/en/function.imagecreatefrompng.php) relies on `fopen()` which can commonly be [disabled in your `PHP.ini`](http://www.php.net/manual/en/filesystem.configuration.php#ini.allow-url-fopen) — Sam, May 01 '14 at 17:21
what if you save it as a file? is it ok? or read it but do not do any processing and send it out. still getting rubbish? i would be trying to find out, at which step, it starts to go wrong. is 'gd' installed correctly etc. — Ryan Vincent, May 01 '14 at 17:59
Yes GD is fine. I can't download it, is like a forum signature.. — Ygor Montenegro, May 01 '14 at 18:04
See the comments in [this answer](http://stackoverflow.com/a/13494645/593090). — klugerama, May 01 '14 at 18:10
There is no BOM in the final source, and no includes in the file to generate this BOM.. — Ygor Montenegro, May 01 '14 at 18:19
@Leo T Abraham that won't make any difference, since double quotes do resolve variables. — Fabian, May 01 '14 at 18:40
@YgorMontenegro does your script work if you move your header declaration higher up in your script, before anything has the chance to be output? — esqew, May 01 '14 at 18:44
@YgorMontenegro May I also ask, why you have so many closing } in your series of if/else statements? That may be the culprit. — esqew, May 01 '14 at 18:47
@esqew, those are fine, i've already tried to comment the whole query section, including the if else part, but i still get no success. — Ygor Montenegro, May 01 '14 at 18:51
@YgorMontenegro you get no success, but does it give you any error after commenting out some of the non-essential code? — esqew, May 01 '14 at 18:53
Appears the same warning in the question, pointing to the same header(); function.. — Ygor Montenegro, May 01 '14 at 18:59

score 7 · Accepted Answer · edited May 04 '14 at 19:02

7

Found it!!!

Well! there was a BOM before the PHP tag. How to remove it, is very very simple. I'm using Adobe Dreamweaver, so here are the steps:

1 - Press CTRL + J (Page Properties);

2 - Go to the title/encoding tab, and uncheck the "Include Unicode Signature" checkbox;

enter image description here

Save the document, and the magic happens. Have no idea why I didn't get this error in the other server!

And if you don't use Adobe Dreamweaver, the Notepad++ can convert to UTF-8 without BOM (Byte Order Mask):

Notepad++: Convert to UTF-8 without BOM

edited May 04 '14 at 19:02

Dinei

4,494
4
36
60

answered May 01 '14 at 19:30

Ygor Montenegro

659
1
12
26

1

Side notes: (i) by the time `ob_start()` line executes PHP has already sent the BOM; this explains the "headers already sent" error with buffering being _on_ (ii) if the output is PNG (or binary data) then the file must not contain the BOM. Otherwise, the two extra bytes in the beginning will break the binary data. – Salman A May 08 '14 at 08:14

score 1 · Answer 2 · answered May 01 '14 at 19:24

The output is correct but its not being recognized as a PNG. The problem is the header is not being correctly set, which is why it is not being recognized. Probably because headers are already set.

Remove ob_start() and see if that fixes it.

Otherwise check the existence of anything that would put another header on it, such as a header PHP file being added by .htaccess.

EDIT: The PHP error confirms this is the case. Something is already setting file headers. It is very likely to be .htaccess adding a header to every PHP file in this directory. This is your problem, as I do not see any other headers or echos on this script.

score 1 · Answer 3 · answered May 01 '14 at 19:31

1

Add ob_start("ob_gzhandler"); . It may fix your problem. Where are your images? In subdirectory or in database?

answered May 01 '14 at 19:31

Ansh

94
4

PHP - imagepng not working properly

3 Answers3