Digital Negative (DNG) is an imaging specification that provides for long-term storage of digital photographs generated in multiple proprietary formats. The specification was released in September 2004 on a royalty-free basis by Adobe Systems. At the same time, a program was released by Adobe that converts image files from most digital cameras into DNG format.
The images that a digital camera originally generates are known as raw image files. Each camera manufacturer has its own proprietary raw image file format. Professional photographers prefer to shoot and store digital images in raw format, because this avoids problems with lossy compression that can occur when files are converted to standard formats such as JPEG.
Unfortunately, there exists no common standard format for raw image files. This can result in compatibility problems because proprietary formats are likely to become obsolete as digital camera technology evolves. The DNG specification was conceived and developed with the intent of eliminating such problems by becoming a standard format for long-term storage and archiving of digital photographs. Market forces will determine whether or not this ideal can be achieved. Some digital camera manufacturers are embracing DNG, but others are resisting it.