Image Processing Reference
1.3 Introduction to Digital Image Editing
1.3.1 Characteristics of Pixel Images
GIMP is used primarily for editing pixel or bitmap images. Pixel images are
made up of tiny dots called pixels; these images are somewhat like mosaics in
structure. All photographic images captured by a digital camera or copied by
a scanner are pixel images. The pixel image is considered standard.
The image dots (pixels) become visible when a pixel image is overly enlarged.
Size and resolution are the most important characteristics to take into
account when manipulating pixel images. Since pixel images are composed
of tiny dots, it can sometimes be tricky to enlarge them. If you overdo it, the
individual dots will become visible and the photograph will lose its integrity.
The size and resolution of an image also determines the file size (i.e.,
storage volume measured in kilobytes or megabytes) of any given image.
Uncompressed pixel images normally result in very large file sizes.