Fabric.js canvas.toDataURL() sent to PHP by Ajax

Question

I have a problem here when I need create a image with transparent background. I still don´t know if the problem is with fabricjs or with php. Everything works fine when I sent a

Answer 1

I don't know if this is exactly the problem you're experiencing, but some of the GD library's imagecreate* functions create images without the alpha channel.

The workaround I've found is to create an image using imagecreatetruecolor and copy your transparent image onto it.

Try a process like this:

$img = imagecreatefromstring($data);
$w = imagesx($img);
$h = imagesy($img);
$alpha_image = imagecreatetruecolor( $w, $h );
imagecopyresampled( $alpha_image, $img, 0, 0, 0, 0, $w, $h, $w, $h );

That should ensure that you end up with a "true color" image with the proper alpha channel.