[RESOLVED] Setting the background color of a PNG

Shock_CNOP

I'm attempting to set the background color of an image, but it doesn't seem to be working. The PNG image has a transparent background to begin with, but whenever I print the image out, the background is always white.

This is the code I'm using:

$clan_cin = "X38-TEK9";

$cnopseal_image = ImageCreateFromPNG("http://www.centraloutpost.com/cnopapproved.png");
$background_color = ImageColorAllocate($cnopseal_image, 0, 0, 0);
$font_color = ImageColorAllocate($cnopseal_image, 255, 242, 0);

$text = $clan_cin;
$font = "silkscreen.ttf";
$size = 6.5;

$xi = ImageSX($cnopseal_image);
$box = ImageTTFBBox($size, 0, $font, $text);
$xr = abs(max($box[2], $box[4]));
$x = intval(($xi - $xr) / 2);
$y = 28;

ImageTTFText($cnopseal_image, $size, 0, $x, $y, $font_color, $font, $text);

header('Content-type: image/png');
ImagePNG($cnopseal_image);

You can see what it produces:
http://www.centraloutpost.com/cnopsys/cnop_sealgen.php

Anyone have any idea why it's not working for me?

coreyp_1

how about adding:

imagecolortransparent($cnopseal_image, $background_color);

Weedpacket

Or switching off [man]imagealphablending[/man] and switching on [man]imagesavealpha[/man] before drawing the background. (You may want to switch them back again afterwards depending on what you're doing with transparency in other parts).

Shock_CNOP

The imagecolortransparent() function isn't changing anything, and the imagealphablending() and imagesavealpha() functions give me a dusky gray background instead of a transparent one. 🙁

Is there a better way to do this maybe? Perhaps change the original PNG in someway in order to make the background transparent?

Weedpacket

So I did some experimentation and found the appropriate place to place the switches is just before the image is saved (i.e., after the text has been added). Works for me (see attached).

If that doesn't look right to you then I'm going to start suspecting that you're viewing the file in Internet Explorer - which is notorious for having the worst PNG support of any application that claims PNG support.

Shock_CNOP

That's it! It's a browser issue. Sad...

Thanks, Weed.