Commons:Overwriting existing files

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This guideline is about when and how users should or should not overwrite existing files.[1] Guidance on this is necessary because both Wikimedia projects using Commons files and external reusers who directly use Commons content rely on files being reasonably stable. As a result, the basic rule is that existing files should not be overwritten with substantially different content, whilst minor improvements should overwrite the previous version (but see below for exceptions). When in doubt, or to resolve inter-user conflicts, upload as a new file.

When not overwriting the existing file, changes should be uploaded under a new name (ideally similar to the old one), and the file description page should link to the original file and give credit to the original author(s).

DO overwrite[edit]

Minor improvements[edit]

✓[OK] As a general rule, use the link "Upload a new version of this file" only for relatively minor improvements. Examples include

  • replacement with higher resolution versions of the same file, however, without using artificial methods to generate higher resolution
  • minor and uncontroversial color correction, noise reduction, perspective correction etc.
  • removal of a watermark
  • needful 90/180/270° rotation or minor rotation corrections of images that are not upright
  • minor cropping
  • uncontroversial corrections to diagrams, maps, or charts, if a more accurate version is available
  • correction of SVG errors
  • adding or correcting translations, fixing spelling errors (e.g. changing "grater" to "greater")

and similar things where the essential composition is not altered. This might include a minor crop, for example to remove a recently-added border (don't upload over with files that remove parts of historical images), but aggressive crops should usually be uploaded under a new name, such as "Old image name (crop).jpg".

Correction of minor errors will usually be considered a minor improvement. However, the more extensive the correction, the more likely that it is better to upload the corrected version as a new file (to avoid possible disagreements about whether the correction is appropriate, and potentially an upload war), and if necessary nominate the old file for deletion.

Note: a file with image annotations will lose those annotations if the pixel dimensions change – see Help:Image-Annotator#Limitations. This is not a reason to split a file when making minor improvements, as the annotations can be re-entered.

Exceptions[edit]

✘ If digital restoration work is being done on a historical document or artwork, the restoration (no matter how minor) should always be uploaded under a new filename from the original file, providing a link back to the source on which it was based in the new file's "other versions" field. The changes that were made should also be documented in sufficient detail to reproduce them, if possible. This is best practice for restorations, because it allows users and subsequent restorers to follow the chain of improvements and to make detailed comparison with the originals. (However, if a restoration already performed to a file, for example, missed a dust spot, it is not necessary to have a new file for each small change in the restoration). In some cases such original files are marked with {{Please-do-not-overwrite-original-files}}.

The symbol for Featured Pictures

? Take care with files that have been awarded a special status like Featured Picture (or the equivalent on another Wikimedia project) as the status applies to a particular file version. Featured Pictures, Quality Images and Valued Images will be identified on their file description pages using {{Assessments}}. (NB the special Commons status does not transfer to derivative files.) The image creator may make minor changes where they feel this would be uncontroversial wrt the promotional status (for example, removing dust spots or fixing a minor tilt). Potentially controversial changes should be discussed with members of the forum that promoted the image.

✘ Files used in Wikimedia projects where the use requires the file to remain unchanged – which means no overwriting at all: not for updates, minor improvements, or error corrections. Comments (including pointing out errors, and pointing to other versions) may freely be made in the Commons file description, but the file itself should not be overwritten. If necessary, upload a new version as a separate file. Such files should be marked with {{Please-do-not-overwrite-permanent-version}}.

✘ Controversial or contested changes. If another editor thinks that the change is not an improvement (even if the editor making the change deems it minor), the change can be reverted, and the new image should be uploaded under a new file name. See below.

Respect content creators[edit]

The original image creator is often the best person to make edits. Since JPG is a lossy format, every edit to a JPG can deteriorate the image slightly; seemingly minor and "beneficial" edits such as changing white balance or adding noise reduction can actually do significant damage. Often the image creator has access to the RAW files from which to make a new version with whatever fix is required. This is always superior to editing the JPG. If it is a photograph, the image creator was there when the picture was taken so will be in a better position to judge whether colours and lighting are correct. Therefore it is strongly recommended that users wishing to make improvements to photographs first contact the creator, whether on Commons or elsewhere.

Unedited versions[edit]

✓[OK] Sometimes users uploading new files that have been edited (e.g. a photograph improved for colour, contrast, etc, compared to the raw photo) may wish to provide the original unedited version as well. Uploading these independently would needlessly clutter categories. The solution is to first upload the unedited version, and then shortly afterwards to upload the edited version over it, so that the unedited version is available in the file history. The unedited versions are not intended to be used independently, and should not be split out as separate files unless this is needed for a specific known use. Files using this approach should be labelled with {{Unedited version}}.

Note: overwriting unedited versions applies only shortly after upload of the unedited version, and only to the original uploader when uploading an improved version of the same file. In all other cases, the usual criteria about overwriting apply (is it minor improvement? etc). In addition, the usual rule about resolving disagreements applies: if another user feels it useful to split the file, it should be split.

Secondary images[edit]

✓[OK] Sometimes users may wish to provide an image related to their upload, which might fall outside the Project scope as an independent file. Examples include images of labels related to the subject of the main image, or the reverse of a postcard as evidence of copyright status. The solution is to first upload the secondary image, and then shortly afterwards to upload the main image over it, so that the secondary image is available in the file history. The secondary images are not intended to be used independently, and should not be split out as separate files unless this is needed for a specific known use. Files using this approach should be labelled with {{Secondary image}}. Note that secondary images are not exempt from the usual requirements of Commons:Licensing.

Note: overwriting secondary images applies only shortly after upload of the secondary image, and only to the original uploader. In all other cases, the usual criteria about overwriting apply (is it minor improvement? etc). In addition, the usual rule about resolving disagreements applies: if another user feels it useful to split the file, it should be split.

Files with current data[edit]

✘ Be cautious about overwriting files with new versions reflecting new information, as in many cases this may not be what reusers want.

✓[OK] However, files may be identified to reusers as ones where information may be updated – these files can and should be overwritten to reflect new information as necessary. Identification may be by the filename, file description, categories, or (most clearly) with the {{Current}} template. A file named "File:Germany location map.svg" is expected to indicate the current boundaries, and is expected to be updated if, for example, the boundaries changed or errors were observed. On the other hand a file named "File:Germany, Federal Republic of location map October 1949 - November 1950.svg" is expected to be correct for that period and not reflect current boundaries.

DO NOT overwrite[edit]

Exceptions to the minor changes rule[edit]

  • Exceptions to the "minor changes should be uploaded to the same file" rule (see above):
    • ✘ Digital restoration
    • ✘ Files that have been awarded a special status like Commons Featured Picture, Commons Quality Image, or similar status on another Wikimedia project. Such files are marked with {{Assessments}}.
    • ✘ Files used in Wikimedia projects where the use requires the file to remain unchanged
    • ✘ Controversial or contested changes – see below.
    • ✘ Artificially upscaling or enlarging using any tool, including AI-based or deep learning services
    • ✘ Removing parts of historical images.
      For instance, historical engravings often have a border, and text describing the image under the image. If it was part of the original composition, and you want to remove it for some use on Wikimedia sites, upload it as a new file. If there are annotations or markings in the image that weren't part of the original composition, these can be removed and placed into the {{Information}} template, without a need to upload as a new image; for example, in the case of the Bundesarchive images, there is usually a call number and date of the photograph.

Substantial changes[edit]

  • ✘ Major changes (e.g. a radical crop)
  • ✘ Changes that reflect different data (e.g. updating a map)
    • ✓[OK] unless the file is marked as updateable – i.e. identified to reusers as one where information may be updated, by the filename, description, or with the {{Current}} template

Unrelated files[edit]

  • ✘ Completely unrelated files
    • ✘ Different files on the same topic (such as a photo of a cow uploaded over another photo of a cow)
    • ✘ Different files relating to the exact same object (e.g. a different photo of Michelangelo's David)
    • Note: do not overwrite a file in order to delete it; follow the Commons:Deletion policy instead.

Controversial or contested changes[edit]

✘ Changes to a file that are likely to be contested should be uploaded to a separate filename. Upload wars (a form of edit war in which contributors repeatedly upload different versions of a file in an effort to have their version be the visible one) are always undesirable. As with other forms of edit warring, users who engage in upload wars may be blocked from editing.

If another editor thinks that a change is not an improvement (even if the editor making the change thinks it's minor), the change can be reverted. Once a change has been reverted, the new image should be uploaded under a new filename (unless the reverting editor explicitly or implicitly agrees to the contested change). This is true even if the change is necessary, in one editor's view, to avoid a copyright infringement: in this case, if agreement cannot be reached through discussion, the old file should be nominated for deletion.

The more known uses of a file there are (through transclusions on Wikimedia projects), the more cautious contributors should be in deciding whether a change qualifies as "minor". Widespread usage of a file makes it more likely that even small changes will be controversial. If in doubt, uploading as a separate file avoids potential surprises for reusers. In some cases, prior discussion with previous uploader(s) or in locations where the file is in use may help decide whether a planned change can be considered "minor".

Changes that break consistency with other images[edit]

✘ When images are consistent among each other, individual images should not be changed in a way that makes them inconsistent with the others. (E.g. File:Icosahedron flat.svg should not have been overwritten with a white version, because that broke the consistency of the set.)

✓[OK] Small changes can be made to all images, as long as they remain consistent. (E.g. it was fine to remove circles around numbers in File:Hawaiian Eruption-numbers.svg, because it was done to all images in the set.)

Examples[edit]

Minor improvements[edit]

See for example the version histories of

Minor improvements for textual elements include correcting spelling on a map's labels. By contrast, translating a map's labels from English to German is a major change, and should be uploaded as a separate file.

Substantial crop or un-crop[edit]

Whether a crop is "substantial" depends partly on the proportion of the image cropped, and partly on how much the excluded content affects the composition. For an image of a museum object on a grey background, cropping much closer to the object was considered a minor crop:

On the other hand, the photograph below of Martin Scorsese was substantially cropped for a closeup on his face, and the result was put into a separate file; and the photograph below of a mountain was cropped to substantially recompose it:

When cropping a JPEG image, remember to always use lossless cropping.

  • Example: This 1899 portrait of a young man with a fish by Wilhelm von Gloeden was uploaded in 2005 but then overwritten in 2010 by a full length un-cropped version. Though the intent was to restore the image to a better quality version, the overwrite proved highly controversial as it changed the context from a modest pose to a nude with potential erotic connotations. In some existing transclusions this change was unwanted and caused controversy. Uploading the higher quality image as a separate file would have avoided this.

Unedited versions[edit]

Secondary images[edit]

  • Example: File:Neapolitan Fisherboy.jpg is an image of a sculpture, and contains an image of the sculpture's label in the file history.
  • Example: File:William Shatner Star Trek.JPG is a publicity photo of William Shatner as James Kirk from the television program Star Trek, and the oldest image in the file history is used to verify the public domain status.

Files with current data[edit]

Examples:

Controversial or contested changes[edit]

Permanent versions[edit]

Linking files[edit]

Attribution[edit]

Be sure to attribute the original author appropriately, and to apply a license compatible with the original file. You can use {{Derived from}} and {{Derivative versions}} to link the files. More specific derivative templates are also available, including {{Image extracted}}, {{Retouched picture}}, and {{Attrib}}.

Using "other versions" field of Information template[edit]

The template {{Information}} has an |other versions parameter which you can use to link between different versions of a file. You can

Link to a variable content[edit]

When you want to provide or use a stable link from the other projects for any image which is anticipated to be repeatedly updated, you have several ways to do it:

  • Label the image page with the {{Current}} template (see § Files with current data). The main disadvantage is that the old version cannot be directly linked if needed.
  • Create a file redirect page under a fictive filename on Commons and use a link to this filename on the other projects. Change the redirect to each new version (inbound links from other projects need not to be updated). This means updating just one link instead of many. (Note the effect of overwriting or switching over can be delayed slightly through cache delay or can fail through software imperfection.) Example: link to File:Africa borders redirect on Wikipedia, and on Commons have File:Africa borders redirect point to File:Africa borders 2011, File:Africa borders 2012, etc as needed.
  • Combine the two methods. Particular version can be uploaded (and linked) separately under their specific permanent filenames and a different filename can be marked with {{Current}} version and overwritten ever by the current version. That means (just as the previous solution) that the current version is available under two filenames: one for the constant content and one for the updatable content. This solution should be more immune towards cache delay and software-update bugs than the previous one.

Warning: when doing one of these solutions, be sure that users of the filename are clear that the content of the file may change, and try to check uses of the file before updating the redirect or overwriting the file.

Notes[edit]

  1. A file can be overwritten by any user with an account older than 4 days from the file's file description page using the Upload a new version of this file link below the File history; or via Special:Upload. Special:Upload provides two warning messages when overwriting an existing file – MediaWiki:UploadFormPreviewOverwriteError and MediaWiki:Fileexists (see also Phab:T41344). The UploadWizard does not allow overwriting of files.

See also[edit]

Help[edit]

Ways to get help
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Other policies and guidelines[edit]