php如何压缩图片大小
首先说下我们网站，网站后台写好之后，是由编辑人员根据需要上传图片，很多图片都是用QQ截图，默认保存为png格式。图片上传的代码的是由同事写的，用的是ueditor，对上传的大小没有进行控制，同事上周离职，将工作交接给了我。上午运维跟我说，我们这个网站占用的带宽太大，追查是因为图片太大的原因。
进入正题：
对于已经上传的图片，如何再压缩图片，或者说在请求的时候，http返回的图片会小一些；同事上传的png图片多达300KB，老板要求控制在50K以下。我现在能做的是，在上传的时候控制图片大小。对于已经上传的怎么解决，不可能一张张改，太废时间了
------解决思路----------------------
写了个批处理程序，可以参考下。
查找目录及子目录的图片文件(jpg,gif,png)，将大于某值的图片进行压缩处理。
http://blog.csdn.net/fdipzone/article/details/39651709
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