<sc:image> now supports the following attributes (bold indicates default values):

field => The name of the image field (same as V5.2).

select => The xpath to the item. (same as V5.2 with '.' as the default value).

allowStretch => Allow stretching the image beyond its original size? Legal values: [true | false]. Same as the 'as' parameter for media URLs.

backgroundColor => Background color for the border added when an image is strecthed beyond its original size (and allowStretch=false). Legal values: Color names (ie. red, blue, etc.) and HTML hex color codes (ie. CE55E2). Same as the 'bc' parameter for media URLs.

database => The name of the database to pull the image from? Legal values are any of the defined database names. The default value is the content database of the current site (if no content database is defined, the regular site database is used). Same as the 'db' parameter for media URLs.

disableMediaCache => Disable the media cache for this request? Legal values: [true | false]. If true, the image will always be retreived from the database, bypassing the media cache. Same as the 'dmc' parameter for media URLs.

height => Height of the image to display. Legal values: Any positive integer. Same as the 'h' parameter for media URLs.

language => Language of the image to display. Legal values: Any valid language name. Same as the 'la' parameter for media URLs.

maxHeight => Maximum height of the image to display. Legal values: Any positive integer. Same as the 'mh' parameter for media URLs.

maxWidth => Maximum width of the image to display. Legal values: Any positive integer. Same as the 'mw' parameter for media URLs.

scale => Scale factor for the image to display. Legal values: Any positive floating point number (note that the decimal separator must always be a dot, as in 3.4). Same as the 'sc' parameter for media URLs.

thumbnail => Request a thumbnail image? Legal values: [true | false]. This can be used for displaying representations of media types other than images (ie. pdf, flash, etc.). Same as the 'thn' parameter for media URLs.

version => Version of the image to display. Legal values: Any positive integer. Same as the 'vs' parameter for media URLs.

width => Width of the image to display. Legal values: Any positive integer. Same as the 'w' parameter for media URLs.

Note that you can also use the shorthand names of these parameters (ie. w, h, thn, etc.).