We are also running v3.30 and have the same issue. I cannot find the changeset the url doesn't seem to work. I understand this is probably fixed in 3.40, but it would create a huge task for us at the moment, so I am hoping to find a fix for v3.30.
Also is the problem the same for other image formats (JPG, PNG, etc)
It seems we are having the same problem with the gif images.. We have Just upgrade our site from 3.9 to the very last version 4.2 but we have noticed that now the gif images have a worst definition from the 3.9 version. Have a look at the follow url https://www.hobbystore.it/idropulitrice-comet-scout-classic
Any idea how to fix it
Thank you for your help
Another question.. In the 4,2 version doesn't exist the bin directory anymore? I cannot find it in the entire site..maybe that's why my gif images are worst than ever