When I mentioned hints I was thinking on the lines of:
– this plugin works well with Imsanity (to ensure images are resized upon upload) and Image Cleanup (to make sure no leftovers are clogging your site, generating bogus information in Ewww Image Optimizer).
I’m not familiar with Image Cleanup, so I’ll have to take a look at it to see what you’re talking about. EWWW is certainly capable of fully compressing images all by itself, so if you could provide a bit more detail that would be great.
I’m updating the EWWW main page with some more information about compatible plugins, but after reading the reviews, I can’t really recommend it. Makes me nervous to even try it on my dev site since it throws notices when I activate it.
However, from the description, it sounds like it just searches the uploads folder for images that are not registered in the database, and gives you the ability to clean them or “index” them (aka register them in the database).
With EWWW that isn’t necessary, as you can instruct it to scan ANY folder on your website for images to optimize. This setting is under Advanced->Folders to Optimize and it will take care of any images that aren’t registered in the database.
This is what your plugin tells me:
16973 images in the Media Library have been selected (15105 unoptimized), with 6815 resizes (0 unoptimized).
Previously optimized images will be skipped by default.
After running the bulk optimization several times it keeps telling me that those images are already optimized:
Full size – No savings – Previously Optimized
This is what Image Cleanup tells me:
Invalid Attachment Meta (14954)
I assumed that these are the same un-referenced images that your plugin doesn’t want to optimize for some reason (although, all of them are in the /uploads/ folder).
That’s why my suggestion was to look at these images and try to optimize them as well, even if they are not linked with posts in the database or are theme size versions of the same image.
Indeed, the advanced settings do provide you this option, but the message provided with the default settings on doesn’t say anything to justify those un-optimized images, hence my suggestion in the opening post.
Even with that option enabled, the message on the bulk optimization page remains the same as mentioned above.
I’ve installed the plugin on other sites as well, and there it optimizes all images.
This particular site has some old content issues that most probably generate these weird messages, but somehow both plugins identify a similar number of images with problems.
