Change threshold to 38%

[zanhecht]

5% is a ridiculously small amount to resize an image by, especially since there is nothing magical about 0.1 megapixels other than it being a nice round number (and that number isn't based on any policy). A 5% change has a huge impact on image quality without any real impact on a proper fair-use claim. I am suggesting 60% to be more inline with DASHbot, which allowed up to a 400px by 400px image, but even a 100% threshold (allowing a 0.2 megapixel image) would still be in-line with the non-free image policy.

[zanhecht]

See https://en.wikipedia.org/wiki/Wikipedia:Village_pump_(policy)#Improve_automated_reduction_of_images for related discussion

[theopolisme]

Nowhere in that thread do I see "60%" mentioned—did you pull this number out of a hat, or was there consensus somewhere that I missed? I do see discussion of a minimum size to reduce in the first place (Masem suggested 0.2 mp, you mention 0.16 mp), but not anything about a 60% threshold.

Thanks!

[zanhecht]

I was basing this on the .16 megapixels based on DASHbot and somewhat of a compromise from Wnt's suggestion of 0.2 megapixels (which he later amended to .16), but I think I did my math wrong (I was calculating the pct as (original-modified)/modified instead of (original-modified)/original). 37.5% should be equivalent to .16 megapixels as calculated in the code.