To change the size of pictures saved on your computer you need a photo-editing software. Photo-editing software allows you to make pictures larger or smaller, crop images or change the contrast of images, among other functions. Resizing a picture with graphics software will allow you to print photos as posters or change them into avatars. With certaint types of software you can change the size of the whole picture or parts of a frame. Many computers have pre-installed software that will resize photos and perform basic editing functions. Writer Bio
