(PHP 4, PHP 5, PHP 7)
imagecolordeallocate — ȡ��ͼ����ɫ�ķ���
$image
, int $color
) : boolimagecolordeallocate() ����ȡ����ǰ�� imagecolorallocate() �� imagecolorallocatealpha() �������ɫ��
<?php
$white = imagecolorallocate($im, 255, 255, 255);
imagecolordeallocate($im, $white);
?>