Convert print, CMYK images to tiled, RGB images for iPhone?

I was given some high-res images, which were originally made for a printed magazine, to show in an iPhone app, like the Xcode PhotoScroller app (like iPhone's native Photo viewer app). I'm down-sizing them to 1024 x 1536 px and I'm going to be slicing them up for use with UIScrollView and CATiledLayer.

1. When I'm resizing them, should I also convert them from CMYK to RGB?

   I think so because RGB is for digital, right? But they also looked fine on the iPhone as CMYK. Why do they say to use RGB for digital?

2. What's the best way to resize them to 1/2 & 1/4 and slice all 3 sizes up?

   1024/4 = 256, so I'm thinking of making every tile (except for t开发者_StackOverflow社区he edge ones) 256 x 256 px. I tried Tile Cutter, which worked, but I have 20 images, so I'll have to do it 20 times. Plus, it doesn't let you put levels deep, so I'll also have to resize each image twice in PhotoShop. So, that's 60 images that I'll have to run through The Cutter. It shouldn't take too long, but odds are, I'll be doing this again, so I'd like to have a better solution. Ideally, it'd be cool to do this with the iPhone, but for now, I think I'll use Paul Alexander's Tile Ruby script unless you suggest a better option. I also might try Zoomify.

---

RGB has a wider range of colors then CMYK.

CMYK is the range of colors printed on a white paper. it stands for Cyan Magenta Yellow and blacK. (think of the 4 colors in your printer cardiges. CMY for colors and K for black.) when miking CMY you have a very very dark grey. It goes on a scale of 0-100% from each color.

RGB are monitors colors. It's the way LCDs and CRTs process colors. With Red Green and Blue. It goes on a scale of 0-255. 255 of both 3 colors makes white.

Now since monitors are backed with backlight, it can make bright color printers can't do. like shiny green or shiny pink. A CMYK picture will look fine on screen. A RGB will lose color on print (like those shiny greens will become matte).

For the iPhone, work on RGB. reasons: - It process directly RGB values - You'll get precise color - RGB takes less memory then CMYK