I want to store output of exec command in array.

[kalashri]

I am running following code.In this code i am extracting all images from pdf.
In this code i am getting all extracted images in my "site" folder from where i am running my php script.

exec("convert -scale 1500x1000 ".$pdf[$i]. " img%d.png");

Now i want to store all the images into paticular array.
because i need to pass that array i.e all the images into another folder on ftp.

Or is there any another way to store all image's as output into a variable or array ?