Last modified: 2011-03-13 18:05:14 UTC
Currently on the English Wikipedia, and I imagine on a great many other WikiMedia wikis, there is a constant tension between respecting user thumb size preferences, and specifying an appropriate size for images. Routinely overruling default thumb size preferences is problematic because: # Users who have explicitly specified a small default because of low screen resolution or low network bandwidth, are served large images against their will; # Specifying a larger image for users with a small default, can result in a smaller image for users who have explicitly set a large default; for example, if someone decides that the 180px is too small for a lead image, and sets the image to 240px, users with a thumb size of 300px end up being served a lead image smaller than the default! # From a server load point of view, it is much better to be serving images at a few standard thumb sizes, as this means more efficient use of the image cache and less on-the-fly scaling. On the other hand, always honouring thumb size preferences is undesirable because: # Some images need to be made larger in order to show critical detail; # Images with extreme aspect values can look unacceptable small or large, and there needs to be a way to overrule that; There is a solution: enhance the image syntax to support keywords "bigger" and "smaller", which would bump the image size up (resp. down) by one default thumb size option. That is, since the default thumb sizes on the English Wikipedia are currently 120px, 150px, 180px, 200px, 250px and 300px, specifying "bigger" will cause an image to be displayed at 200px for those with a default thumb size of 180px; at 250px for those with a default thumb size of 200px; etc. Providing this option would allow flexibility in setting image size, while still respecting user settings. It would, I believe, result in much more prevalent display of images at the standard thumb sizes (together with the two edge cases: "smaller" on a 120px default; and "larger" on a 300px default"). The result for the servers should be much more efficient image caching. In order to ensure that the effect of "bigger" and "smaller" is fairly consistent across all default thumb sizes, there needs to be a constant(ish) ratio between adjacent thumb sizes. The simplest way to do this is to set the 120px "smaller" to 100px, drop the 150px default to 145px, drop the 180px default to 175px, increase the 200px default to 210px, and set the 300px "bigger" to 360px. This would result in the following set of thumb sizes: {100px, 120px, 145px, 175px, 210px, 250px, 300px, 360px}, which very nearly represents a constant ratio of 1.2.
See also bug 2581.
WONTFIX this bug because the requested feature can be handled by with "upright" parameter: [[Image:name.jpg|thumb|upright|description]] = automatically reduced to 75% of the user preferenced image width [[Image:name.jpg|thumb|upright=1.2|description]] = automatically increased to 120% of the user preferenced image width [[Image:name.jpg|thumb|upright=0.5|description]] = automatically reduced to 50% of the user preferenced image width This is far more flexible than "smaller" or "bigger" keywords.
