I am working on optimizing site load speed for a few moderately high traffic sites. Some quick observations show that creating 40 picture thumbnails (e.g. 138×138 JPG @75% quality) results in 700 Kb total size with embedded metadata and 258 Kb with stripped metadata. Which means that roughly 60% of image size is metadata.
So what would be pros and cons of removing metadata from thumbnails? Are there any regulations, e.g. you must keep author info / copyright info in the images?
Any insights would be appreciated.
There are no copyright regulations, in most countries, which require you to include copyright information in the metadata; the Berne Convention (an agreement that many countries, including the US, adhere to) says that copyright must apply to any work, from the moment of creation, without registration or notice being necessary. Most, if not all, of your users will never look at the metadata. There’s pretty much no point in preserving it in thumbnails; just strip it off, and improve performance for your users, which they do care about.