An image that is the same or very similar to an already existing image.
Duplicates should not be confused for the following:
- image sample, an image typically used by sites to load images faster.
- md5 mismatch, an image that is different (has a different md5) from the image at the source.
- revision, an image that has been revised by the artist from a previous image.
- scan, a image that has been scanned from another source.
A few cases where the tag may be found:
- Exact duplicates. Duplicates (images with the same md5) currently cannot be uploaded anymore.
- Images with identical pixel data, but different metadata.
- Lower resolution versions of the same image.
- Resized images. Note that duplicate resized images should not be tagged with md5 mismatch.
- Images of generally lower quality and that may contain jpeg artifacts.
Before you upload an image, try to seek if it has already been uploaded by using the IQDB image search or the "Find similar" button.
Duplicates are tagged manually. There is no system in place to accurately tag duplicates given how easy it is to confuse duplicates for the above, unless such duplicates are also image samples where their original is already uploaded.
Do not flag duplicates for deletion if your only reason is that the image is a duplicate.
Not to be confused with multiple sources, although they may overlap sometimes.
- multiple sources is about outside sources -- it means that multiple copies are available outside Danbooru.
- duplicate is about Danbooru -- it means that we have multiple copies of the same image.