TRIM
This submenu contains a choice of options for trimming the edges of the picture.
-- Trim to selection: Trims the picture to the area under the selection marquee.
-- Trim color 0: Trims the picture to the smallest bounding rectangle that is not color 0.  This effectively trims off all the unused white space around a picture.
-- Trim white: Similar to above, except it trims white, or if there is no white, the color closest to white.
-- Trim black: Similar to above, except it trims black, or if there is no black, the color closest to black.
-- Trim solid edges: Similar to above, except it trims every edge that has the same color along the entire edge.  It keeps doing this until all solid edges have been trimmed.