Flickr Upsets Users By (Apparently) Boosting Compression
Some users of Yahoo's photo sharing and hosting website Flickr have taken to the Internet with upset comments, expressing issues with the quality of their lesser-sized photos. Namely, the sized-down non-original photos appear to have more compression artifacts than they used to, suggesting that Flickr has made some silent tweak that cuts down on data numbers while (very slightly) lessening the visual quality of many images. Flickr has issued a statement on the matter, though it dances around actually confirming whether a change has happened.
Flickr works by presenting "thumbnails" of original images, with those thumbnails coming in a range of sizes (including fairly large ones). This makes it faster and easier for someone view and share an image, but also results in some compression — understandably so. If one wants to see the original image without any secondary compression, they can.
Nothing about that has changed — the original images are still available and are identical to whatever is uploaded. The issue some users are having, however, is that the differently sized thumbnails appear to be more compressed than they previously were, and the result is some noticeable artifacts, slight losses in details, and such (when viewing anything but the original image).
The folks at PetaPixel did some contrasting and comparing, and there does indeed seem to be some extra compression happening with the resized images.
In a statement to them, Flickr said that it "does not compress originals ... Like most photo apps, we create several sizes of thumbnail images for the purpose of showing images quickly on the web and in the mobile apps ... To optimize the user experience, from time to time we make changes to how these thumbnails are created."
This isn't any issue for most, as the originals remain untouched. Some photographers have expressed concern that viewers won't always realize that the resized images are compressed, however, and may mistake compression artifacts as the fault of the photographer.
SOURCE: PetaPixel