Linked Open Data for Digital Still Image Formats

Digital still images are digitally encoded representations of the tonal and brightness information of a subject into a bitmap. Data from digital cameras and scanning devices record light characteristics as numerical values into a grid or raster of picture elements (pixels). There are two types of raster file digital image categories: Digital still photographs of natural, real-world scenes or subjects produced by digital cameras, and scanned images of textual documents, illustrations, posters, graphics, cartographic records, photographic prints, slides, and negatives. Image file formats are standardized means of organizing and storing rasterized data that can be used on a computer display or printer.

The significant properties of digital still image records are documented in the Digital Still Image Preservation Plan, which can be used as test criteria for tools and processes used in format transformations. 

NARA makes its Linked Open Data available in Resource Description Framework Terse RDF Triple Language or RDF Turtle (.ttl files). These files can be opened in any text editor. The Digital Preservation Framework as Linked Open Data includes the same elements as are available in the version of the Preservation Plans on GitHub.

These plans are not exhaustive nor universally applicable proposed actions and recommended or endorsed tools: these represent file formats and variant versions in NARA holdings, the current NARA risk assessment, processing capabilities, and tools in use at NARA.