[PHP] $x <> base64_decode(base64_encode($x)) for imagecreatefromstring

[James Coder]

I'm writing a script that does image manipulation, and trying to take 
some of the images I use in an imagecopy() out of the filesystem as 
images, and put them directly in the php file as strings assigned to 
variables.  Of course, they're binary so they garbledygook everything if 
they're not converted, so I want to convert them with base64_encode.  To 
test this I have a test script that makes me think that this may be 
impossible, and that there may be a weird bug somewhere in this php 
version.  Weird thing is, the string works ok if it's read with fread or 
imagecreatefrompng, and then directly output with imagepng.  However, if 
this data is encoded with base64_encode as $x1, and $x1 is then decoded 
as $x2 with base64_decode, imagecreatefrompng($x2) hangs (php produces 
no output it seems, none either from code prior to imagecreatefrompng() 
), even if the script determines that all these values are identical 
(with the === operator and strcmp() ) on scriptruns when the critical 
line imagecreatefrompng($whatever) is commented out.

Sample: (run on 4.3.4)

 if (is_file($filename)) {
  $fd = @fopen($filename,"r");
  $image_string = fread($fd,filesize($filename));
  $image2 = base64_encode($image_string);
  $image3 = base64_decode($image2);
//  echo strcmp($image_string, $image3);             commented line 0
  if($image_string <> $image3) die('not equal');
//  if($image_string === $image3) die('same type');  commented line 1
  if(!$image3) die('none');
//  echo 'got here';                                  2
  $im = imagecreatefromstring($image3);
//$im = imagecreatefromstring($image_string);         3
//  echo 'and here';                                  4
  imagePNG($im, 'thisimage.png');
//  echo 'and here';                                  5
  header('Content-type: image/png');
  imagePNG($im);
  imagedestroy($im);
  fclose($fd);
}
when commented line 0 is uncommented, the script outputs 0, output for 
strcmp in cases of equality.  and 1 makes the script die('same type'). 
When commented line 3 is uncommented and the line before it commented 
out, the script works fine.  When the commented echo lines are 
uncommented (when the script uses imagecreatefromstring($image3)), php 
seems to produce no output.

I'd greatly appreciate any advise on getting the image source into the 
php file itself, and on why this is behaving so oddly.  Also: is this 
likely to be more load-intensive than just reading in the image files 
with imagecreatefrompng or fopen?

Thanks,
James Coder
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