Hi, I'm trying to create an automator workflow that will make icons from pictures I have. The steps are to take each image, Pad and Scale the image so that the canvas is 102x102 (The image has to be in the center, but automator does that automatically), add icon to the file name and save it in a different location

I got the workflow to do this beautifully, but the only problem is that the edges are black. If this were done in MS Paint (like I've been doing), when I change the canvas size to be bigger the area it adds is white. Because of the rules, the extra area does have to be white and if I can't get "preview" to do this for me I can't use it

So the main question is, does anybody know how to make the program preview use white pixels instead of black when the image is scaled/padded? Or, does anybody know of a way to do this in GIMP/Photoshop so that I could incorporate it into the workflow?