Applescript droplet to generate png previews using LDView

Code:
property ldview : "/Applications/LDView/LDView.app/Contents/MacOS/LDView"

on run
	set root to choose folder with prompt "Please select folder."
	generatepreview(root)
end run

on open root
	if folder of (info for root without size) is true then
		generatepreview(root)
	end if
end open

on generatepreview(root)
	
	set suffix to "\\( -iname \"*.ldr\" -o -iname \"*.mpd\" -o -iname \"*.dat\" \\)"
	
	set root to (POSIX path of root) as string
	set root to quoted form of ((characters 1 through -2 of root) as string)
	set ldrs to do shell script "find " & root & " -type f " & suffix
	
	repeat with ldr in paragraphs of ldrs
		try
			set dirname to do shell script "dirname " & quoted form of ldr
			set png to ((characters 1 through -5 of ldr) as string) & ".png"
			do shell script "cd " & dirname & "; " & ldview & " " & quoted form of ldr & " -SaveSnapshot " & quoted form of png
		end try
	end repeat
end generatepreview