When you use photos for documents or other projects you may sometimes find that they aren't big enough. If you are working in a program that does not have interpolation, the result will be a fuzzy image with jagged edges. To reduce this effect, use a program like GIMP to upscale -- which is another way of saying "enlarge" -- your images. The process is quick and easy.
Load the image you want to enlarge onto your computer.
Start GIMP. In the dialogue that pops up, browse to and open the image you want to enlarge.
Select "Image" from the menu. Choose "Scale Image." In the dialogue box, set the "Interpolation" to "Cubic." Increase the width and height to what you want and click "OK." Save your work.