PHP: image*() - functions provide invalid images - php

Question

Following code:
class FilesController extends Controller {
public function icon($fileId) {
$this->uses("FileAttachment");
$FA = new FileAttachment($fileId);
$fnth = $FA->path . 'th___' . $FA->filename;
$this->View->render = false;
if (file_exists($fnth)) {
$imageinfo = getimagesize($fnth);
switch ($imageinfo[2]) {
case IMAGETYPE_JPEG:
$image = imagecreatefromjpeg($fnth);
Header("Content-type: image/jpg");
imagejpeg($image);
break;
case IMAGETYPE_GIF:
$image = imagecreatefromgif($fnth);
Header("Content-type: image/gif");
imagegif($image);
break;
case IMAGETYPE_PNG:
$image = imagecreatefrompng($fnth);
//Header("Content-type: image/png");
imagepng($image);
break;
case IMAGETYPE_BMP:
$image = imagecreatefromwbmp($fnth);
Header("Content-type: image/bmp");
imagewbmp($image);
break;
}
}
imagedestroy($image);
}
}
produces broken images. The image is shown in a browser just as a broken one. The file exists, otherwise there would come nothing. My Windows shows the pictures correctly. What can be the cause?
PS. If I remove Header, the browser displays the image's binary content, so it actually looks OK...

Answer 1

Your code is rather pointless - you're forcing PHP (and gd) to do a bunch of useless work to load up the file, decompress it into memory, and then recompress it for output.
Why not simply have:
$info = getimagesize($path_to_file);
header('Content-type: ' . $info['mime']);
readfile($path_to_file);
?
As for your code, check the entire output of the function. If there's ANY php warnings/errors being produced, they'd get embedded in the output and general cause "corrupt" images.

Answer 2

imagecreatefromgif(); //returns an image resource
Have you tried to add at the bottom ?
readfile($image); //reads a file and writes it to the output buffer.