Hey,There is an step in dam update asset called EPS thumbnail, if you
configure this step in the web enabled step there is a way to configure
the quality, try that might help. In the quality field you can put some
value ex.75 if you want quality of 75 %Its good that you create a new
workflow for generating rendition using that step only, instead of
changing the default workflow. Please download your existing image from
dam and check their pixels, if they are of good quality.