I need a PHPCLASS to online conversion picture: PNG to ICO (windows format); PNG to ICNS (MAC format); hope is efficient, of course I will not change the picture than 512PX.

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我需要一个PHPCLASS 用来在线转换图片：PNG to ICO（windows格式）；PNG to ICNS（MAC格式）；希望是高效的，当然我转换的图片不会大于512PX。