Commons:Media for cleanup

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While some images uploaded to Commons are in great shape, many have some kind of problem. While we can't fix some problems, such as a poor angle or out-of-focus photo, many can be fixed after the fact with digital editing. This page describes just a few of the most frequently encountered issues, how to fix them, and gives examples of them.

Images that need to be cleaned up are listed at Category:Images for cleanup and in its many subcategories. If you find an image that needs improvement, and it does not fit under one of the more specific scenarios below that has its own tag, add {{Cleanup image|explanation}} to its description page to mark it for cleanup.

Contents

[edit] Images with unnecessary borders

Some images present borders that are not necessary and contain redundant information (such as description texts). These include images with excess white or black "padding" on the sides. If you see an image like this, add {{remove border}} to it, which adds it to Category:Images with borders.

What to do: trim the image to the relevant area only. If cropping a JPEG, consider using a lossless cropping tool such as jpegtran. You can also use Cropbot. If the cropped area contained text, be sure to include it in the image description.

Example: Before, After

[edit] Images with non-free frames

Similarly, some images include nonessential decorative elements such as 3D frames that are legally problematic and need to be removed. In particular, PD-Art images may not contain 3D frames. If you see an image like this, add {{Non-free frame}} to it, which adds it to Category:Images with non-free frames.

What to do: If the frame is rectangular, crop the image to the area of the free image only. If cropping a JPEG, consider using a lossless cropping tool such as jpegtran. You can also use Cropbot. If the cropped area contained text, be sure to include it in the image description. If the frame is round, oval, or some other odd shape, use an image editing tool to select the area containing the free image, then invert it and blank the rest to white or (for PNGs/TIFFs) transparent. If you are an admin, you may wish to delete the old revision containing the border.

[edit] JPEG images that should be PNG or SVG (see Wikipedia:Image use policy#Format)

Certain images (practically anything but photos) look and work better (and may require less room) in either a lossless format or a vector graphics format, for which we use PNG and SVG files respectively. These generally include flags, graphics, icons, diagrams and certain screenshots (such as from old video or arcade games, but not newer ones with high color depth). If you see an image like this, add {{BadJPEG}} to it, which adds it to Category:Images with inappropriate JPEG compression. Also consider {{Convert to SVG}} if applicable.

What to do: Remake the image or retouch it (making it sharp) using image editing software, as described at w:Wikipedia:How to reduce colors for saving a JPEG as PNG. You should not convert JPEG files directly into PNG files without modification, since this won't improve quality and will just make a larger file. See below for some advice on SVG. Note that a new file will have another name. Once done, mark the old image with a {{superseded}} tag.

Example: Before, After

[edit] PNG photos that require a JPEG version

Although PNG is not a bad way of losslessly storing photographs, any thumbnail of a PNG appearing in an article will be in PNG format. The result is that these thumbnails have a large filesize, making them slow to download for many users (typically, about 10 times larger than JPEG thumbnails). Although ideally the software would be able to create JPEG thumbnails of PNG images, right now it can't.

What to do: Create a JPEG version of the file and upload it; quality is not important when we do it this way as long as it looks good. Place {{PNG with JPEG version}} on the original PNG's page and {{JPEG version of PNG}} on the JPEG's page. This alerts people to refer to the JPEG version in articles, but to make edits to both versions, based on the PNG version.

Example: PNG before, PNG After, JPEG after

[edit] PNG or JPEG images that should be SVG

Images composed of simple shapes, lines, and letters are often better expressed using vector graphics. These have a number of advantages such as making it easier for subsequent editors to edit them, enabling arbitrary scaling at high quality, and sharp high-resolution renderings for print versions. If you see an image like this, add {{Convert to SVG}} to it, which adds it to Category:Images that should use vector graphics. Certain JPEGs and PNGs are not suitable for transfer to the SVG format. These include heavily or artistically shaded images, or non-free images on other projects such as those of logos (conversion to a scalable format can represent a copyright violation). Images that have been uploaded at a high resolution and good quality are a lower priority for transfer to the SVG format. Efforts are better focused on converting lower quality, smaller images that will be substantially improved if redrawn in as a SVG. Images which will appear the same but obviously requiring marginally less file space and the ability to resize and translate are a lower priority.

Raster images generated by libre(free) software programs, for which a source file is made available under a libre license, is also of lower priority. In fact, such images if the source file is provided should be left alone probably if the program does not provide SVG output, or else it may even be *harder* for subsequent editors to modify the image (the opposite of the stated goal above).

What to do: using vector graphics production software (see en:Comparison of vector graphics editors), remake the image. The original image can often be used as a template. Some notes:

  • A very simple image with known dimensions and colors, like a plain flag, may be easier to make from scratch.
  • A raster image can be vectorized, but be careful: it will almost certainly differ from the original and need some manual work. Do not leave the raster image in the SVG when saving it for upload. Check for redundant code which does not affect rendering (but don’t forget about scalability).
    • Sometimes people base their images on a raster “thumbnail” from a WMF project. See the next item.
    • Raster images based on the vector or raster maps from Commons should often be not just vectorized, but remade based on those maps (see Blank maps, SVG maps, Maps).

[edit] Pictures that are scaled down from their original resolution

Partly because Mediawiki image pages scale down images by default, it's a common mistake to upload a scaled-down, lower-resolution image to Commons than the original image. This is unnecessary and undesirable; large images are necessary for use in print and other situations. If you see an image like this, add {{thumbnail}} to it, which adds it to Category:Images uploaded at reduced resolution.

What to do: Upload or locate a larger resolution image of the same filetype. If the image is otherwise identical, tag it with {{duplicate|Image:example.jpg}} and give for the parameter the larger image. You or the person deleting it should use "check usage" to ensure that the small image is no longer used. See Commons:Deletion guidelines#Duplicates for more information. If the larger image has differences, tag the old version with a {{superseded}} tag instead.

Example 2 (differences): Smaller version before, Smaller version after, Larger version

[edit] Sideways pictures or pictures with noticeable camera tilt

These images need to be rotated so they're upright. For slightly tilted images this may involve cropping and/or cloning to remove or fill in new areas. If you see an image like this, add {{rotate}} to it, which adds it to Category:Images requiring rotation. If you want to rotate images by 90, 180, or 270 degrees add the parameter |degree=90/180/270 to let it rotate automatically by Rotatebot (e.g. {{Rotate|degree=90}} or simply {{Rotate|90}} to rotate 90° clockwise). Although Rotatebot uses jpegtran to losslessly rotate JPEG images, the rotation is not completely lossless as images of sizes which are not a multiple of the JPEG block (16 × 16 pixels for color images, 8 × 8 pixels for grayscale images) have to be cropped to the block boundary.

[edit] Pictures that need to be retouched, trimmed and scaled

These include images with captions that are too small to read or photos that contain irrelevant surroundings. Dark and unclear pictures should also be properly modified. Background colour of graphics and diagrams should be white.

If cropping (only) a JPEG, consider using a lossless cropping tool such as jpegtran. You can also use Cropbot.

If the cropped area contained text, be sure to include it in the image description.

[edit] Images containing regular noise, texture, or interference

A variety of sources can introduce unwanted overlaid patterns into an image, such as electromagnetic interference, poor reception of a signal, or scanning from a newspaper.

What to do: Ideally, find a better version of the picture that does not contain the noise. If this is not possible, in many cases you can clean up this type of problem using Fourier analysis. For more information on how to do this, see Commons:Cleaning up interference with Fourier analysis. You can also add {{cleanFFT}} to the image, which adds it to Category:Images containing regular noise.

[edit] Low quality pictures

Some pictures are not sufficient to clearly demonstrate the subject of the picture; whether by being too blurry to digitally fix, not properly demonstrating the subject of the image, or being visually unappealing in another way. New versions with higher quality should be found and used instead. Low-quality images can be tagged with {{low quality}} to add them to Category:Images of low quality.

What to do: get a camera and take a better picture, or try to find one under a free license. See, for example, meta:Help:Public domain image resources, meta:Free image resources, Commons:Free media resources and Commons:Public domain and free image resources — a free image search engine (which also includes Commons)

[edit] Pictures, graphs, slides and diagrams in a specific language and/or script

Some pictures use inside descriptions or captions in a specific script or language.

What to do: redesign the picture to describe the elements with colour codes and/or numbers, in order to achieve a language neutral form. This would allow its use in all Wikimedia projects and, more importantly, all Wikimedia languages. If you see an image like this, add {{Convert to international}} to it, which adds it to Category:Images requiring internationalisation.

Note that language specific files are acceptable, especially for complex diagrams, if there is a language-neutral version as well. Such files should be linked to each other. It is also less important for SVG files to have a language-neutral version, as it is easy to edit these to modify the language.

[edit] Versioning

For cleaned up media, a rule of thumb is to:

  • first upload the original, dirty media;
  • upload the cleaned up version over the dirty version.

This allows the dirty version to be recovered if desired, but not included or linked to directly.

Alternatively, one can upload the cleaned up version under a different name; this is particularly useful if several different clean-ups are done. See discussion on cropping.

[edit] See also

Retrieved from "http://commons.wikimedia.org/wiki/Commons:Media_for_cleanup"
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