My image became pixelated/blurry after I enlarged it.
All JPEGs, GIFs, PSDs, and other raster images are made up of pixels, or dots. If you enlarge your image without resampling it, the same number of dots will be spread out over a larger area. Resampling corrects for this loss of resolution by creating additional pixels and assigning them colors that blend well with those of the original pixels. If you resample a red circle on a blue background, for instance, the feature will produce a couple of purple tints for the new pixels that surround the circle: reddish-purple inside, blueish-purple outside.
If your image becomes blurry or pixelated after you resize it, it has not been resampled properly. This usually occurs when the number of colors available in your palette is too small to create the desired effect.
Below are general instructions for enlarging an image without losing resolution. To learn the specific procedures for each step, see your software's help documentation.