How to resize image without losing EXIF data?

How do i resize an image without losing too much quality?

• I have photos that are 10x6 in. 240 dpi. I need to resize them to 13x9. I dont want to lose too much quality, what would be the best way? should i lower the dpi when i resize it?

• Answer:

  It doesn't matter too much, just increase the size. The best thing you can do is just use a good program that will do a better job of extrapolating the pixels. Lowering dpi will give you lower quality, but there is no point in raising it either. Each dot of a distictly different color (right now you have 14400 of them: 10x6x240) is still going to be a distinct dot when it gets blown up. Even if your resolution is higher or a little lower in the resulting pic, the amount of dots that make up each of those colors will be the same block of color. Think of it like you have a pic that is just 1"x1", and 2dpi. There are two dots on that pic, lets make one red and one orange. If you blow that up to be 2"x2", then half of the pic is still orange and have is red. If you leave the resolution at 2dpi, then since there are now 4 sq inches, there will be four identical red dots clustered, and 4 orange dots clustered, but since they are the same color, it doesn't matter if there are 8 small red dots, or 1 big red dot in the resulting pic. The only reason to lower the dpi would be if you want a smaller file size, though, because a good program will look at the extra dots/pixels that it is creating when it blows something up and try to make the best guess as to what that new dot's color should be. If it were part of a bigger image, the red and orange example, it might create new pixels that are reddish orange inbetween to smooth the color transition because it knows if it keeps the blocks separate it will look more pixelated when blowing up, so it trys to counter that by adding what would logically be a pixel betweenween those if there were to have been one in the first place.