512x512 image for the iPhone app

Question

I am about to submit my first app to the iTunes App Store. The docs say that the application needs to be submitted with a "512x512 px, 72ppi, RGB, flattened, no transparency JPEG image".

I have a couple of questions:

1. RGB - what exactly does it mean in this context.
2. Flattened - does it mean that if I am creating the image in Photoshop, I should flatten all the layers? Doesn't saving to JPEG kind of imply that? Or does it mean something completely different.
3. No transparency - JPEG doesn't support it to begin with. What color should the background be then?

Answer 1

1. RGB means to ensure that you save the image as an RGB (rather than CMYK) JPEG. This is very likely to be the case already. (You can change the colour mode via the 'Image -> Mode' menu in Photoshop if you have the icon in the CMYK colour space for some reason. That said, all images destined for on screen usage should remain with the RGB colour space.)

2. As you say, directly saving as a JPEG (or doing save for web) will flatten the layers for you.

3. Whatever colo(u)r you want it to be. (i.e: It'll appear as saved.)

Hope that makes sense.