Slow script when run as an application

Question

I have created a script for processing images with Photoshop. When I run the script from Script Editor it completes its task literally twice as fast as when I run it as an application. Does any one have an explanation as to why this would be the case?
The script in summary asks the user for 2 folders, it then pairs up images from the folders, opens them both in Photoshop, copies the paths from one image to the other, crops the image and saves a copy in the appropriate place, then moves on to the next pair of images.
I don't understand why it woud run twice as sluggishly as an application?
Any suggestions much appreciated.

Answer 1

Rien,
I have also consistently seen the same problem, and asked a similar question a couple of years ago without a satisfactory response. If you write an AppleScript studio application your script will run at about the same speed as when running the script from script editor.
To observe the problem you just need an application script that is communicating information back and forth betweent the script and the application it is driving, and then check out the performance difference between running it as an application or not. If you run Activity Monitor you can see that the cpu spends plenty of its time idle when running the script as an application.
If you grab a copy of iMagine Photo from:
http://www.yvs.eu.com/downloads/iMaginePhoto.dmg
and get PhotoScript1 from about 1/2 down the following page:
http://www.yvs.eu.com/documentation/readingandwritin.html
Run the script from both within script editor and as the application droplet.
It demonstrates the problem. But I have seen worse, this was just the first script on my website that I found that demonstrates the problem.
Kevin