How do I make an image bigger w/o distorting it?

get a better camera with higher magapixels and take the picture with it

Not really.. All a computer can do is guess what might go between pixels. This process is known as dithering.

If it is line art you could trace it in a program that uses vectors and blow that up. But if it is a picture of something you are kinda stuck with what you have.

You can use a more sophisticated program. Photoshop does an OK job of stretching and interpolating. There is some even better specialized software that does this, such as Genuine Fractals, which tries to figure out the shape of what’s shown, and actually does an interesting job even on small images, but of course it is making up information.

Actually, the process is called “interpolation” – where Photoshop (or whatever editing program you’re using) guesses at what the pixel values should be in between the existing ones.

Imagine is you had a small patio composed of 20 bricks. You decide you’d like to make it bigger, so you space those twenty bricks apart by a foot or so. What goes in the empty gaps inbetween? If you’re smart like a person, you’d add matching bricks. If you’re dumb like a computer, you ‘d make your best guess at what goes in between – maybe bricks, maybe pasta.

@PupnTaco – I would have thought the computer would just make the bricks bigger, not space them out and put things in between. If you make an image, say, four times bigger on a computer, than each pixel is made four times bigger.

Generally, no – you can do something like that with Indexed-color images like GIFs but as a standard, Photoshop will guess at what goes in between. So if one pixel is red and the one next to it is green (as a crude example), Photoshop would guess at a muddy olive as the new in-between pixel – and create some blurring gradient pixels to smooth the transition. That’s why resized images start looking blurry and funky-weird.