Photo CD was an optical disc system based on the Compact Disc that allowed the storage of up to 100 high quality images in a proprietary format. It was introduced by Kodak in 1992, and the format is defined in the Biege Book standard (one of the Rainbow Books covering Compact Disc standards). Kodak’s Photo CD system also included the scanners for photo processing labs that could take scans from film negatives or slides. Photographers could take exposed film to a Photo CD processing lab, where the film would be developed and scanned to a Photo CD, or they could have previously developed film scanned to Photo CD.
Photo CDs were designed to be played on a dedicated standalone Photo CD player connected to a domestic television, but they could also be played in a CD-i player. It was possible to play them on a computer with suitable software, but at the time CD-ROM drives were still uncommon.
The system was not popular with consumers, though it was more accepted by professional photographers. Although there were around 140 Photo CD processing labs in the US alone by 2000, by this time domestic scanners enabled consumers to scan their own photographs. In 1999, Kodak had also introduced the more affordable Picture CD system, with images in JPEG format burned onto a recordable CD that also held the software required to the view and edit the images on a computer.
Kodak had completely abandoned the Photo CD business by 2004, but never released the image specifications. However, it has been reverse-engineered so it is possible to convert images to other formats.