imagecreate inside an object

[Lorenzo Marussi <info@xxxxxxxxxxxxxxxxx>]

hello list,

I'm trying to manage a image resouce inside a method, but
unsuccessfully...

In detail, that's some code snippets:

the class and the method:

class.php

class canvas{

    function makeImage($imageWidth = 850){

        $im = imagecreate(110, 20) or die("Cannot Initialize new GD
image stream");
        $background_color = imagecolorallocate($im, 0, 0, 0);
        $text_color = imagecolorallocate($im, 233, 14, 91);
        imagestring($im, 1, 5, 5,  "A Simple Text String", $text_color);
        return $im;
    }

}

... than my test.php file:

header("Content-type: image/png");
include_once("class.php");
$c = new canvas();
imagepng($c->makeImage());

the result in the browser isn't the image itself, but an error that
sounds like: (I traslate the message from italian):
"Image can't be displayed because contains some errors"

but... if I comment out the "header" line, I get this:

‰PNG  ��� IHDR���n���
���V,š���PLTE���é[an÷���fIDAT•c` `fxÄÀÃ`Ç
ÀçÀ
ä²41ƒ‚€˜Ë–Ý’Àq²@੤;{á0— œi

...sounds like a png image, isn't it? but It doesn't :-/

The code in the method is very simple, is the same of the php manual
page of "imagecreate" function, and I think the resource is correctly
managed, 'cause if I write this:

$c = new palinsestoCanvas(3);
imagepng(null);

I get: "Warning: imagepng(): supplied argument is not a valid Image
resource" 

.. so I think $c->makeImage()) returns successfully the resource.. but I
still didnt see my image..


Any help is appreciated, thanks

Lorenzo