Help:Image guidelines

General guidelines

 * Images used on the Wiki should be uploaded directly to the Wiki using the upload page. This avoids inline linking (also known as hotlinking) or external linking of images on external sites. This is to avoid a number of problems:
 * Stealing bandwidth from other sources (leeching)
 * Copyright ownership
 * Availability
 * Ensuring the image links are more reliable, as they are under our control
 * The Portal Wiki is not an image hosting service, and any images uploaded to the Wiki should solely be for use on the Wiki, not your personal website or any other place.

Source, author and copyright information

 * Each image on the Wiki has a corresponding description page. On that page, you should document the copyright status of the image by selecting one of the pre-defined licenses. Unlicensed images will be subject to deletion. Please see the licensing help page for more information on the correct license to choose when uploading images.
 * You should add the source and, if known the author of an image in the summary section when uploading, or use the  template.
 * Fan art images should rarely be uploaded. In an exceptional case where fan art is relevant and notable, it should always be marked as non-official, especially when used in an article, and they should not take precedence over official artwork.

Naming

 * Use descriptive titles. Suffix the filename with the content description. For example, acceptable filenames would be "File:bots_highfive.png" or "File:Atlas_Tyrants_helm.png". File names such as "File:forscience.png" or "File:youmonster.png" are not descriptive, and will be subject to being renamed or deleted.
 * Lowercase file extensions should be used for uniformity (ie .png rather than .PNG). This is also important as the software treats image names as case sensitive&mdash;this means "Filename.PNG" is considered a different file from "Filename.png".
 * Avoid uploading images of the same subjects under different names. It is better to overwrite an existing image with a better one than to upload it to a new name (unless the current name is not descriptive enough, or the file is using a different format). Images can be reverted back to previous versions if newer ones are deemed to not be improvements.
 * Use of underscores in image names is unnecessary as spaces in file names will be replaced with underscores.  is the same as.
 * Images uploaded for use in userspace should be prefixed with  where   is the user who uploaded that image, and will be using it on their own userspace.

Categorization
Using categories for your images helps us sort them better, and makes it easier to find that particular image, should it be relevant for an article in the future. Your image should always reside in at least one category; more if relevant. To place an image in a category, simply add, substituting CATEGORYNAME for the relevant category.


 * Icons should be placed in one or more subcategories of Category:Icon images.
 * Screenshots should be placed in one or more subcategories of Category:Screenshot images (this will be automatic if you use the  template).
 * Userspace images should be placed within the Category:User images category, by inserting  into the image's summary field.

Additionally, a full list of all available categories can be found on the page Special:Categories. Should an appropriate category not exist, create a new one as necessary.

Image formats
Currently png, gif, and jpeg image formats are allowed. All of these formats have different uses, and should generally be used for different types of images.


 * png should be the primary file format for all images, unless otherwise noted. This includes, but is not limited to, icons, low-color illustrations (signs, icons, etc.), screenshots, in-game art, and similar images.
 * jpg should only be used for photographs, when the source image is a jpg, or when cropping the png to make it fit the size limit is not an option.
 * gif should only be used for animated graphics, or when the original source is a gif image.

Image size

 * Larger images may be difficult for some users to download or view so it is recommended that you crop images to focus on their subject.
 * It is possible to upload images of up to 2MB. If you cannot remain within this, consider re-sizing or cropping your image before saving it as a lossy file format.

Compression levels

 * png can have their file-size reduced by lowering the number of unique colors in the image, due to the way png files are compressed. It is, however, not recommended to do so, as it lowers the quality of images significantly.
 * jpg files should always be uploaded at 100% quality, to avoid as much artifacting as possible. That said, it usually shouldn't be necessary to refactor jpg images, as they should only be used when the source is a jpeg, and thus require no editing.

Optimization programs can be used to reduce file size; consider using programs like RIOT if you have Windows, or PunyPNG for an online tool&mdash;both of which handle jpg, gif, and png files.

Resolution

 * Crop non-landscape images to show the important areas.
 * Do not upload huge images&mdash;try to keep to a width of around 1280 (1280x1024 XSGA for 5:4 aspect ratio, 1280x960 for 4:3, or 1280x720 WXGA for 16:9).
 * Do not blow up small images to larger sizes without good reason; this can detract from the overall quality.
 * It is not recommended to resize images in an editing program, as MediaWiki can scale images automatically. Uploading a larger image that is cropped neatly means that higher amounts of detail can be seen if necessary.

Transparency

 * Images that require transparency should use the png file format. Gifs can also handle transparency, but only in a single indexed color as they only support 256 colors and do not have alpha channel support. This means they do not allow anti-aliasing of edges or blended color layers, and shouldn't be used on the wiki for those reasons.

Image linking

 * Inline linking (also known as hotlinking) or external linking of images on external sites for display on Portal Wiki should not be used. There are multiple reasons for this including bandwidth leeching, copyright, ownership and availability issues.