我很确定我需要使用imagefilledrectangle来获得白色背景而不是黑色......只是不确定如何.我尝试了几种方法.
$targetImage = imagecreatetruecolor($thumbw,$thumbh);
imagecopyresized($targetImage,$sourceImage,0,0,0,0,$thumbWidth,$thumbHeight,imagesx($sourceImage),imagesy($sourceImage));
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