Digital photograph restoration

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.

Before (top) and after (bottom) of an old portrait. Scratches have been removed using FaceApp's Retouch tool, and the app Remini was used to significantly increase the photo's resolution.

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.

Background

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 photographics, but preservation of a photograph’s digital surrogates has become of equal importance.[1]

Handling practices

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.[2] Creation of digital surrogates allows originals to be preserved.[3] However, the digitization process itself contributes to the object’s wear and tear.[4] and it is important to ensure the original photograph is minimally damaged by environmental changes or careless handling[5]

Permissible uses

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.[6] 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 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.

Example of the digital image restoration of a severely water and mildew damaged 5x7 inch glass photographic plate of the Golden Gate in San Francisco, California, taken about 1895 from "Land's End" in Lincoln Park on the Northwest tip of the San Francisco Peninsula.
An example of digital image reconstruction and restoration of the image "Doi călușari "
Digital construction and restoration of a badly damaged photograph from Costică Acsinte Archive
Before and after composite on a restoration of a 1911 portrait of baseball player Ed Walsh
A restoration project that interpolates features within the frame of the original, including the man's hair and shirt texture.
A restoration project that extrapolates features beyond the edges of the original.
Photographs of documents may be restored, as here, using brightness and contrast and sharpness adjustments, and de-speckling.
Photograph (1942) of a roadside sign has slant and foreshortening issues corrected with rotating and 'skew' functions. Brightness, contrast, and sharpness adjustments enhance distinctness.
Photograph of 1858 newspaper article had skewing and foreshortening issues (shown with yellow lines not in original), and presented gross variations in lighting. Image was corrected by skewing tool, and by adjusting lighting and midtone contrast.
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See also

References
  1. https://greatlibraryexpectations.wordpress.com/
  2. https://www.nedcc.org/free-resources/preservation-leaflets/6.-reformatting/6.6-preservation-and-selection-for-digitization
  3. https://archivehistory.jeksite.org/chapters/chapter1.htm
  4. https://siarchives.si.edu/what-we-do/digital-curation/digitizing-collections
  5. https://www.bl.uk/britishlibrary/~/media/bl/global/conservation/pdf-guides/preservation-of-photographic-material-guide.pdf
  6. Malaro, Marie; DeAngelis, Ildiko Pogany (2012). A legal Primer on Managing Museum Collections (3 ed.). Washington, D.C.: Smithsonian Books. p. 191.
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