Image Events and eps files

Has anyone had any luck with this Image Events script and eps files? The script is solid (written by Apple) and works with jpg, png, tiff, & gif files, but not eps. I do not get any error, but nothing processes either. The new file never gets created.

set this_file to choose file without invisibles
	tell application "Image Events"
		-- start the Image Events application
		set the new_format to PNG
		set the nme_ext to "png"
		-- derive new name for the new image file
		copy my derive_filename(this_file, nme_ext, "-", "") to {new_name, target_HFSpath}
		-- open the image file
		set this_image to open this_file
		-- save in new file. The result is a file ref to the new file
		set the new_image to save this_image as new_format in file target_HFSpath with icon
		-- purge the open image data
		close this_image
	end tell
	-- 	tell application "Finder"
	-- 		-- delete the original file
	-- 		delete this_file
	-- 	end tell
on error error_message
	display dialog error_message buttons {"Cancel"} default button 1
end try

on derive_filename(this_item, new_extension, increment_separator, target_folder)
	-- A sub-routine used for deriving the name and path of a new file using the name of an existing file
	-- Pass in file ref in alias format, the new name extension, an increment separator, and any target directory (in alias format)
	-- Name and HFS path for new file are returned. The name is incremented if a file exists in the target location.
	-- Pass a null string for the target directory to use the item's parent directory
	-- Pass a null string for the new name extension to use the item's current name extension
	tell application "Finder"
		if target_folder is "" then
			set the target_folder to the container of this_item
		end if
		set the file_name to the name of this_item
		set file_extension to the name extension of this_item
		if the file_extension is "" then
			set the trimmed_name to the file_name
			set extension_separator to ""
			set the trimmed_name to text 1 thru -((length of file_extension) + 2) of the file_name
			set extension_separator to "."
		end if
		if the new_extension is "" then
			set target_name to file_name
			set target_extension to file_extension
			set target_extension to new_extension
			set target_name to (the trimmed_name & extension_separator & target_extension) as Unicode text
		end if
		if (exists document file target_name of target_folder) then
			set the name_increment to 1
				set the new_name to (the trimmed_name & increment_separator & (name_increment as Unicode text) & extension_separator & target_extension) as Unicode text
				if not (exists document file new_name of the target_folder) then
					set the target_HFSpath to ((target_folder as Unicode text) & new_name)
					return {new_name, target_HFSpath}
					set the name_increment to the name_increment + 1
				end if
			end repeat
			set the target_HFSpath to ((target_folder as Unicode text) & target_name)
			return {target_name, target_HFSpath}
		end if
	end tell
end derive_filename

It is not a supported file format. Image Events is basically access to SIPS. ESP is postscript and can contain all sorts of data. Images,Vectors & fonts. although an eps file could just contain a single image.

I figured it was something like that. Thanks for reply.