Is the attribute background useless?

[ZhangChengLin]

https://github.com/Gregwar/Captcha/blob/a84b5b450d89fc89aebcfb06b4bbc421c12b797f/src/Gregwar/Captcha/CaptchaBuilder.php#L430

Is the background useless? It is still related to distort in line 480, because $bg in line 480 does not necessarily work. I am not quite sure, so I dare not submit a PR rashly, please confirm.

https://github.com/Gregwar/Captcha/blob/a84b5b450d89fc89aebcfb06b4bbc421c12b797f/src/Gregwar/Captcha/CaptchaBuilder.php#L480

[visavi]

Yes, there is a problem with this, but you can turn off all the effects, then it will work

$builder->setBackgroundImages($backgrounds);
$builder->setIgnoreAllEffects(true);