Compass: generate Sprites, plus width / height on each images in the sprite

This works:

@include all-<map>-sprites(true);

But you may want to consider the documented way of using configuration variables:
http://compass-style.org/help/tutorials/spriting/

You just specify the config variable before the import. In your case:

$ico-sprite-dimensions: true;
@import "ico/*png".
@include all-ico-sprites;

Sending true to the all include works, but as it’s undocumented, it would seem that configuration variables are the preferred method.

Aside from dimensions these are the other configuration variables available:

$<map>-spacing           // space in px around the sprites
$<map>-repeat            // whether to repeat the sprite bg
$<map>-position          // the x position of the sprite on the map
$<map>-sprite-base-class // the base class (default ".<map>-sprite")
$<map>-clean-up          // whether to delete old image maps
$<map>-<sprite>-spacing  // spacing, for individual sprites
$<map>-<sprite>-repeat   // repeat, for individual sprites
$<map>-<sprite>-position // position, for individual sprites