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Full Version: image compression: how does webpagetest check if an image can be compressed??!?
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hey! I was wondering how exactly webpagetest figures out if an image could be more compressed or not, so I could test/tweak stuff see if my site is generating the "right" sized images

i gave a shot at looking at the source and found this constant in wpt_test.cc:37 which looks like maybe a clue... ->

37:static const BYTE JPEG_DEFAULT_QUALITY = 30;

*bump bump*
The code you're looking for is actually here: https://github.com/WPO-Foundation/webpag...ks.cc#L327

It recompresses jpegs at a quality level of 85 which is pretty generous (usually you can go down to 75 without even thinking about it). The process also strips out meta-data like exif tags.
cool! thanks Pat! Big Grin Smile Wink Angel
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