Photo manipulation software allows photographers to correct, adjust or otherwise alter photographs using a computer. By adjusting the individual pixels that make up the images, users can quickly achieve effects that once took hours of painstaking work in the darkroom. Expert users of photo manipulation software can create changes undetectable to the eye, with results potentially similar to the work of a Hollywood special-effects artist.
Adobe Photoshop is by far the most well-known photo manipulation program. In fact, the word “photoshopping” has come into widespread use to describe photo manipulation, whether Photoshop is actually used or not. Adobe discourages this practice, as it risks turning their trademark into a generic word like “aspirin.” There are actually many photo manipulation programs available, including Paint Shop Pro, Corel Photopaint, and the freeware program, GIMP.
Many people use photo manipulation software to correct personal photos, such as fixing the “red eye” effect created by flash photography. Removing extraneous parts of the picture, called cropping, is also a popular feature. Other common tasks include enlarging part or all of a picture, rotating the image, and adding text. User-friendly interfaces of these programs allow the untrained user to attempt even more complex image manipulations.
Expert users can manipulate any aspect of a photograph, or in fact, any image saved in various popular file formats, including jpeg and tiff. Lighting, colour, and even people or objects in the image can be changed, moved, added or deleted. Multiple images can be fused together seamlessly by a user with patience and a steady hand. Photographers, painters and comics artists use the software to achieve artistic effects or clean up rough and unfinished images.
Popular websites such as Worth1000 encourage amateur and professional artists to display their manipulated images. The results often circulate by e-mail, sometimes with unintentional results, as when a manipulated image of a shark attacking a low-flying helicopter was promoted as a genuine National Geographic photograph. In 2006, the news organisations Reuters and AP faced scandal when a photographer admitted he manipulated photos of the Lebanon War.
Aside from Adobe’s issues with the term “photoshopping,” photo manipulation can be controversial when applied to news photography or other areas where "undoctored" photos are expected. The National Press Photographers Association forbids manipulated photos in its guidelines, but alter photos have appeared in noted publications such as Newsweek, Time, and, National Geographic. The new field of “digital forensics” studies images to determine whether they have been altered with photo manipulation software.