Because everyone has their own idea of what defines quality, here are some examples of what we typically consider to be too low to be accepted on the site.
Remember, picture quality and image quality are two different things. A good photo or piece of art can be said to be a quality picture, but if it's reproduced in some way that makes the actual image poor, it's not quality overall.
This is a pretty good shot IMO, but close up it's a mess:
These are JPEG artefacts caused by high compression. It usually makes pics look blocky.
This is an upscale, or a pic that's been stretched. In this case it means rough, pixellated edges.
Another upscale, but this one's sampling means it looks blurred and out of focus instead.
Sometimes noise is artistic, and most photos have some amount of it. However, when it's excessive like here, because of the quality of the shot or the camera used, it's not okay.
Other things:
- High resolution doesn't necessarily mean high quality, but you can often downsize high-res pics to get a clearer image. Remember to save at JPEG quality 100, which pretty much means as little compression as possible.
- Re-saving JPEGs as PNGs does not improve their quality. If a source file isn't saved as PNG to begin with, it's already lost some image fidelity. Maximum-quality JPEG is fine in most cases anyway - you only really notice it in images with sharp lines, so PNG is best for vectors, infographics, etc.
- If you have even more time to fiddle with wallpapers, hunt down the original copy and we'll love you (maybe).
