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:Image use policy - Misplaced Pages

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Rules of thumb

Here's a quick checklist of rules for use of images. After the list, a more detailed discussion explains the reasoning behind them.

  1. Always describe the image and where it came from on the description page. See Image Description page section below.
  2. Give the image a clear title that is unlikely to clash. "Washington.jpg" could be a a map or an image of the US state, the village of Washington in County Durham, or Washington DC; the former president of the USA, George Washington or any of the statues and memorials dedicated to him!
  3. Don't use tiny thumbnails; make small but viewable images 150-250 pixels across.
  4. Crop the images to show just the relevant subject.
  5. If you think having a larger image is necessary, include an ":image:..." link to the larger version on the description page of the smaller. Also include an ":image:..." link to the smaller version on the description page of the larger.
  6. Don't put rendered images on the description pages; they are for text.
  7. Don't put photo credits in articles or on the images themselves; put them on the description page.
  8. Use JPEG format for photographic images, with moderate quality settings.
  9. Use PNG format for icons, drawings, maps, flags, and such; but...
  10. Never convert a JPEG original to PNG; if JPEG is all you have, go ahead and use it.
  11. Do convert GIF images to PNG, except for "animated" GIFs.
  12. Encode sounds as 32K-64K bitrate mono Ogg Vorbis files.

Details

The primary and most important policy is this: the purpose of the upload facilities of Misplaced Pages is to allow authors to upload illustrations to accompany articles. Don't upload images just because they're interesting, or because they might be useful in an article. Just upload ones that will actually be used.

Just like the articles, it is important that images follow the same guidelines about copyrights. Make sure you own the image, or that it is in the public domain, or that the copyright holder has agreed to license it under the GFDL. If the image is copyrighted and used here either with the author's permission or under fair use doctrine, make sure that fact is noted on the description page (see below).

Also like articles, they may be edited or deleted by others if they think that serves the purpose of making a better encyclopedia.

Image description page

Each uploaded file has an associated description page into which you can put text, and which shows the image's history and usage. This page should ideally include all of the following information, but if you don't know something, just put whatever you can:

  • brief description
    • Image of a goldfish in a small tank
  • Where the image came from
    • Photograph taken on 3 March 2003
    • Taken from the BBS News website
    • Scanned from copy of 1911 encyclopedia
  • Author of the image and any other credits
    • Photo by Fred Jones
  • If other versions (especially a larger version) of the same image exists, link to them
    • ]
    • ]
  • Copyright status
    • public domain: copyright expired
    • placed in public domain by photographer
    • released under the GFDL
    • released under the GFDL - in response to the boilerplate request for permission, Fred Jones said "That'd be fine"
    • copyrighted image - the author has given Misplaced Pages permission to use this image, but third parties may not use it without permission
    • copyrighted image - may only be used under "fair use" rules
  • Relevant links (internal and external)

Please avoid:

  • Adding a description in a language other than English.
  • Adding images themselves on the page

Image titles

Descriptive titles are also useful. Uploading a file named, for example, "Africa.png" is likely to collide with one already present, and doesn't give any clue about its contents. A more descriptive name like "Africa_map_2002.png" is better. Avoid special characters in filenames or excessively long filenames, though, as that might make it difficult for some users to download the files onto their machines.

Do not put image credits in the articles using the image. There are four reasons for this: Firstly, the image might be used in more than one place, and so such glosses might go out of sync. Secondly, information purely about the image might be lost when the article is edited. Thirdly, it puts irrelevant information in the article; information about the image itself belongs on the image description page. Finally, it allows lengthy image descriptions to be given without affecting the flow and readability of articles that use the image.

Images themselves should not contain any rendered text such as credits, subject identification, and so on. Information about the image should go onto the image description page where it will be readable by users with non-visual browsers, and where it can become verbose without becoming distracting. The image file may contain embedded comments, as is common in PNG and JPEG images, but preferably not so much as to increase download time. For example, a copyright notice and statement of license under the GFDL would be good to include.

Use appropriate format and size

This scalebar is red from 0 to 100 pixels, yellow from 100 to 150, green from 150 to 250, yellow again from 250 to 300 and red again from 300 to 400 pixels.

There are many technical hints in this section that some people may not have the tools or expertise to deal with themselves. If, for example, you find a great image that needs to be cropped, resized, or recoded and you don't know how to do that, ask someone on the Misplaced Pages-L list to do it for you.

Scale and crop images to a size appropriate for the article. Keep in mind that many readers are using 800x600 displays, and so images wider than 300-400 pixels may overwhelm the article. Larger images also take more time to download over slow links. Likewise, images smaller than 100 pixels wide may be difficult for users of larger displays to see. An optimum size for images with text flowing around them would be 150-250 pixels. Images without text on the side can be wider.

Of course image complexity is an important factor to consider when sizing images. Don't use tiny "thumbnail" images linked to a large image--use an image of the appropriate size; adding a link to a larger version (perhaps the original source) is fine as well, but don't upload the larger one unless it is really needed. A good way to do this is to put a link to the larger image (or to its description page) on the description page of the smaller one.

Drawings, icons, political maps, flags and other such images with limited colors should be in PNG format, preferably grayscale or indexed color with fewer than 200 colors. GIF images should be converted to PNG before upload unless they are "animated" GIFs. Do not use PNG for "photographic" images, unless that (or GIF) is the only format available.

Photographic images should be in JPEG format, with quality settings set to make a reasonably sized file. Do not use JPEG for iconic images or maps (except possibly for photo-like maps that show terrain and such).

If you find an original of a map or flag in JPEG format, only convert it to PNG if this reduces the file size. You may want to check if areas of the same color are not in fact areas of slightly differing colors because PNG compresses same-color areas much better. Your image editor's fill tool or Posterize command may be of help here.

See Misplaced Pages:How to reduce colors for saving a JPEG as PNG for a description of possible conversion pitfalls and how to overcome these.

In particular, most of the maps from the CIA World Factbook website are incorrectly coded as JPEG. If you have the tools and knowledge to do so, render the original PDF maps at high resolution, then rescale them and convert to indexed PNG. The result will be both a higher quality image and a smaller file than the JPEGs from their site. If you can't find the original PDFs, but have the knowledge and skill to convert them to indexed PNGs, do so. The difference in file size can be tremendous.

Here's how to perform such a conversion using the free GIMP image editor:

  1. Open the PDF in in Adobe Acrobat Reader.
  2. Make sure that the interpolation method is set to Cubic (in File | Preferences | Environment).
  3. Take a screen shot of the PDF and import it into GIMP. If you're using Microsoft Windows, press the Print Screen key from within Reader, switch to GIMP, and choose File | Acquire | From Clipboard.
  4. Crop the screen shot to only the map.
  5. If the image is not RGB, convert it to RGB (Image | Mode | RGB).
  6. Scale the image to a size of about 360 pixels (Image | Scale Image... and replace the larger pixel dimension with 360 and click OK).
  7. Convert to Indexed mode (Image | Mode | Indexed...), making sure to use no dithering. Experiment with the number of colors (Edit | Undo) until you have struck a good compromise between simple color and a good iamge.
  8. Save as PNG (File | Save As...), making sure to uncheck all the checkboxes and set the compression level to 9.

However, if you don't know what you are doing, then go ahead and use the original JPEG.

Try to avoid cropping or otherwise editing JPEGs too frequently--each edit creates more loss of quality. If you can find an original of a photograph in 16-bit or 24-bit PNG or TIFF, edit that, and save as JPEG before you upload.

Avoid images that mix photographic and iconic content. Though CSS makes it easy to use a PNG overlay on top of a JPEG image, the Misplaced Pages software does not allow such a technique. Thus, both parts must be in the same file, and the quality of one or the other will suffer. In particular, do not use photographs with text captions on the image itself. Upload the image and add the caption in plain text to the article or to the description page.

Resizing

When resizing large pictures to smaller ones for thumbnails:

  • Crop out unimportant background.
  • If possible, use an exact ratio, eg 3:1, 2:1, 4:1.
  • Work direct from the largest resolution available - if you have a 2048pixel version, work from that, not the 800pixel version uploaded.
  • Consider file size as well as image size - sometimes a version with more pixels but fewer bytes is preferable.
  • When making a thumbnailed version to replace someone else's (presumably inferior) thumbnail, please keep the same name as the original.

Recommended software

These software packages have been recommended by wikipedians for use in image manipulation:


Sounds

Sounds should be encoded in Ogg Vorbis format, generally with a 32K to 64K bitrate. Speech samples should be in mono and perhaps at even smaller bitrate; music samples can be in stereo if necessary. Use only short samples, and try to keep them under 100K. If they are large, include the size of the file in the link so that users are warned that they may have a long download, like this: SAMPLE (202K).

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