if usingInDesignCS5orNewer then
set properties of clipping path of item 1 of all graphics to ¬
{clipping type:photoshop path, applied path name:"Path 1"}
else -- InDesign CS4 or older (not sure how far back this works)
set properties of contour option of item 1 of all graphics to ¬
{contour type:photoshop path, contour path name:"Path 1"}
end if
-- this will resize the parent rectangle to the bounds of the image clipping path
fit given frame to content
-- get the bounds of the rectangle, which now match the bounds of the image clipping path
set {t, l, b, r} to geometric bounds -- top, left, bottom, right
set {w, h} to {r - l, b - t} -- width and height, if desired
end tell
end tell