B 站活动页面这张 563*88 的图片有 20M？

https://www.bilibili.com/blackboard/activity-5hanayome.html

刚刚打开 B 站《五等分的新娘》的活动页面时，发现加载特别慢。于是 F12 找了一下原因，结果发现了一张图片大小足有 20M，关键下载下来一看就是最顶上的标题图，分辨率才 563*88。

图片源地址： https://activity.hdslb.com/blackboard/static/20190109/30cb1f6c4bfeb93761cf35c27d9b88cb/rJv7IFQfN.png

看着这个文件楞了半天想起来用 ps 看了下文件信息，发现了 20M 的原因，图片的原始数据里有超长一大堆。
关键的部分我直接放文本了，因为对 rdf 不了解，所以来问问。

本来是想问的，结果发帖时搜到的相关问题，好像是 ps 有 bug，有时会无端塞入大量无用的 DocumentAncestors 数据，参考链接 tieba.baidu.com/p/5166418760
可以用 ps 脚本删除这些数据，或者导出为 web 所用格式。
虽说现在带宽高了，流量也不值钱了，但给网页供图时还是要有点减小图片体积的意识（不然导出为 web 所用格式干嘛用呢），20M 的图片 B 站员工都没觉得不正常吗。

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