[1] Page Speed Optimization Libraries: net_instaweb::CriticalImagesBeaconFilter Class Reference ( 版) http://modpagespeed.com/psol/classnet__instaweb_1_1CriticalImagesBeaconFilter.html

Inject javascript for detecting above the fold images after the page has loaded. Also adds pagespeed_url_hash attributes that the beacon sends back to the server. This allows the beacon to work despite image URL rewriting or inlining.

[2] ( 版) http://wha2up.com/category/staffdiary

<img src="http://wha2up.com/wp-content/uploads/2015/05/210x70xrogo.jpg.pagespeed.ic.0mUFWYk5aL.webp" width=210 height=70 valign="center" pagespeed_url_hash="3404950283" onload="pagespeed.CriticalImages.checkImageForCriticality(this);">