How to improve the avatar image quality?

The avatar (user profile image) is by default resized on the server-side in order to reduce the amount of data transferred to the client (your browser). As a consequence the quality of the image is reduced. You can improve it in 3 ways:

• configure XWiki to not resize the avatar image at all by setting the following in xwiki.properties:
  rendering.imageDimensionsIncludedInImageURL = false
• configure the image quality by setting the following in xwiki.cfg:
  xwiki.plugin.image.defaultQuality = x

  where x is a number between 0 and 1. The default quality is 0.5. Of course, the amount of data transferred to the client increases with the quality (and size) of the image.

• write a better ImageProcessor component, which is responsible for resizing the image on the server side. Check out the default implementation for a reference. See XWIKI-7623.