Digital photograph restoration
This article is about the restoration of photographs and other documents using digital techniques. For the mechanics of altering images, see Image editing. For the uses, cultural impact, and ethical concerns of image editing, see Photo manipulation. For direct physical restoration of non-digital documents, see Conservation and restoration of books, manuscripts, documents and ephemera.
Before and after images: this restoration extrapolates features beyond the edges of the original.
Digital photograph restoration is the practice of restoring the appearance of a digital copy of a physical photograph which has been damaged by natural, man-made, or environmental causes or simply affected by age or neglect.
Digital photograph restoration uses a variety of image editing techniques to remove visible damage and aging effects from digital copies of physical photographs. Raster graphics editors are typically used to repair the appearance of the digital images and add to the digital copy to replace torn or missing pieces of the physical photograph.
Evidence of dirt, and scratches, and other signs of photographic age are removed from the digital image manually, by painting over them meticulously. Unwanted color casts are removed and the image's contrast or sharpening may be altered in an attempt to restore some of the contrast range or detail that is believed to have been in the original physical image. Image processing techniques such as image enhancement and image restoration are also applicable for the purpose of digital photograph restoration.
Agents of deterioration
Photographic material is susceptible to physical, chemical and biological damage caused by physical forces, thieves and vandals, fire, water, pests, pollutants, light, incorrect temperature, incorrect relative humidity, and dissociation (custodial neglect). Traditionally, preservation efforts focused on physical photographs, but preservation of a photograph's digital surrogates has become of equal importance.[unreliable source?]
Fragile or valuable originals are protected when digital surrogates replace them, and severely damaged photographs that cannot be repaired physically are revitalized when a digital copy is made. Creation of digital surrogates allows originals to be preserved. However, the digitization process itself contributes to the object's wear and tear. It is considered important to ensure the original photograph is minimally damaged by environmental changes or careless handling.
Digitally scanned or captured images, both unaltered and restored image files are protected under copyright law. Courts agree that by its basic nature digitization involves reproduction—an act exclusively reserved for copyright owners. The ownership of an artwork does not inherently carry with it the rights of reproduction.
Images that are digitally reproduced and restored often reflect the intentions of the photographer of the original photograph. It is not recommended[according to whom?] that conservators change or add additional information based on personal or institutional bias or opinion. Even without copyright permission, museums can digitally copy and restore images for conservation or informational purposes.