Photo CD - History

History

The Photo CD system was announced by Kodak in 1990. Photo CD targeted a full range of photographic needs, ranging from consumer level point-and-shoot cameras to high-end professionals using large format 4x5 sheet film. The first Photo CD products, including scanners for processing labs and Photo CD players for consumers, became available in 1992. The project was expected to be a $600 million business by 1997 with $100 million in operational earnings. Kodak entered into a number of partnerships grow the usage of Photo CD. This included, for example, an arrangement with L.L. Bean in 1992 by which the catalog would be distributed in Photo CD format, and an arrangement with Silicon Graphics in 1993 to make all Silicon Graphics image-processing workstations capable of accepting Kodak Photo CD optical disks. These measures, together with the then relatively low cost of $3 per image and convenience, made Photo CD the digital imaging solution of choice for many photographers in the mid to late 1990s.

By 2000, over 140 Photo CD processing labs in the USA were active, with many more outside the USA. However, by the late 1990s, Photo CD was being eclipsed by alternate formats, mainly based on the industry standard JPEG format. In the consumer segment, the Photo CD format’s relatively inefficient compression scheme meant that Photo CD files were significantly larger than a JPEG files of similar quality, and thus less convenient for transmission across the internet, etc. For example, a 16Base Photo CD image of 5.5 Mb can be encoded as a JPEG image of 2.1 Mb at 80% quality, visually indistinguishable from the original. When the Photo CD format was designed in the early 1990s, a design goal was to allow low cost playback-to-TV devices. At that time the available technology precluded 2-dimensional compression schemes such as JPEG, but by the late 1990s, advances in microprocessor technology had moved JPEG/PNG compression to well within the range of even very low cost consumer electronics.

In the professional and advanced amateur segments, Photo CD had been eclipsed by low cost desktop scanners such as those from Nikon and Minolta in the mid range, and by drum scanners at the very high end. While the pixel resolution of Photo CD was still comparable or better than the alternatives, Photo CD suffered from a number of other disadvantages. Firstly, the Photo CD color space, designed for TV display, is smaller than what can be achieved by even a low cost desktop scanner. Secondly, the color rendition of Photo CD images changed over time and with different scanner versions; 4050 scanners had different color rendition to earlier versions. Thirdly, the dynamic range of scans was lower than for desktop scanners. Tests at the time indicated that the dmax rating (a measure of maximum density obtainable) of Photo CD was 2.8-3.0, while commonly available desktop scanners were reaching 4.2, a substantial difference. As a result of this, and Photo CD’s problems with color rendering, by 2004 the professional segment of the user community had generally turned against Photo CD.

In the retail segment, while Photo CD was initially relatively popular with consumers, it was largely an economic failure for processing labs. At the time of its introduction, Kodak claimed that processing costs to labs would be close to $1 per image, which would allow the lab profitably sell at the $3 per image mark. However this promise was never realized, often resulting in the scanning process being rushed, with a resulting fall in quality. As a result of Photo CD’s loss of market share and substantial corporate losses, partially attributed by Kodak Management to its scanning business, Kodak abandoned the format over the period 2001-2004. By 2004, Kodak 4050 Photo CD scanners were being offered for free to anyone that would pay for their removal by more than one processing lab. This abandonment generated considerable controversy both at the time and subsequently as the Photo CD format’s technical specifications have never been released by Kodak. Photo CD remains an often quoted example of an “orphan format” and of the dangers of proprietary image formats within photographic circles.

Despite Kodak not releasing the specifications for the Photo CD format, it has been reverse engineered, so allowing images to be converted to more modern formats. The original reverse engineering work was performed by Hadmut Danisch of the University of Karlsruhe, who deciphered the format by studying hex dumps of Photo CD files, and subsequently wrote hpcdtoppm, which converts Photo CD Images to PPM format, in the early 1990s. During the early 1990s, hpcdtoppm was extensively distributed as part of various Linux distributions, but has since been almost entirely abandoned due to concerns about hpcdtoppm’s restrictive license conditions and lack of color management. However, Hadmut Danisch’s reverse engineering work has been used to create a number of other open source implementations of Photo CD decoders such as ImageMagick. In 2009, pcdtojpeg was created under the GPL open source licence. Also acknowledged by the author to be based on Hadmut Danisch’s reverse engineering work, pcdtojpeg allows Photo CD metadata to be decoded, is color managed, and can decode all known variants of Photo CD files. Currently hpcdtoppm and pcdtojpeg together form the core of information available in the public domain on the technical details of the Photo CD format.