Rainbow Storage is a developing paper-based data storage technique first demonstrated by Indian student Sainul Abideen in November 2006. Initial newspaper reports of the technology were debunked by multiple technical sources, although Abideen says those reports were based on a misunderstanding of the technology.

Abideen received his MCA from MES Engineering College in Kuttipuram in Kerala's Malappuram district.

The Rainbow data storage technology claims to use geometrical shapes such as triangles, circles and squares of various colors to store a large amount of data on ordinary paper or plastic surfaces. This would provide several advantages over current forms of optical- or magnetic data storage like less environmental pollution due to the biodegradability of paper, low cost and high capacity. Data could be stored on "Rainbow Versatile Disk" (RVD) or plastic/paper cards of any form factor (like SIM cards).

Criticism of Rainbow Technology

Following the wide media attention this news received, some of the claims have been debunked by various experts; however, Abideen says that the articles are all based on misunderstandings.

Some of this criticism includes the following ideas: Printing at 1,200 dots per inch (DPI) leads to a theoretical maximum of 1,440,000 colored dots per square inch. If a scanner can reliably distinguish between 256 unique colors (thus encoding one byte per dot), the maximum possible storage is approximately 140 megabytes for a sheet of A4 paper–much lower when the necessary error correction is employed. If the scanner were able to accurately distinguish between 16,777,216 colors (24 bits, or 3 bytes per dot), the capacity would triple, but it still falls well below the media stories' claims of several hundred gigabytes.

At least one of three things must be true for the claim to be valid:

The paper must be printed and scanned at a much higher resolution than 1,200 DPI,

the printer and scanner must be able to accurately produce and distinguish between an extraordinary number of distinct color values, or

the compression scheme must be a revolutionary lossless compression algorithm.

The theory is: If Rainbow's "geometric" algorithm is to be encoded and decoded by a computer, it would equally viable to store the compressed data on a conventional disk instead of printing it to paper. Printing something as dots on a page instead of bits on a disk will not change the underlying compression ratio, so a lossless compression algorithm that could store 250 gigabytes within a few hundred megabytes of data would be revolutionary indeed. Likewise, data can be compressed with any algorithm and subsequently printed to paper as colored dots. The amount of data that can be reliably stored in this way is limited by the printer and scanner, as described above.

Demonstration of Rainbow Technology

Sainul Abdeen demonstrated his technology to the college and members of the Indian press in the MES College of Engineering computer lab, Kerala, and was able to compress 450 sheets plain text from foolscap paper into a 1 inch square. He also demonstrated a 45-second audio clip compressed using this technology on to an A4 sheet. Depending on the sampling frequency, bit depth, and audio compression (if any), a 45-second audio clip can consist of anywhere from a few kilobytes to a few megabytes of data. Abdeen claimed that the technology could be extended to 250 gigabytes by using specific materials and devices. Sainul is now in collaboration with a UK-based company, working on the technology and a portable scanner and printer for use with it.

Notes


"Data Can Now Be Stored on Paper" by M. A. Siraj, ArabNews (published November 18, 2006; accessed November 29, 2006)
Paper storage man misunderstood - The Inquirer article, 12 December 2006 (retrieved 15 December 2006.
"Store 256GB on an A4 sheet" by Chris Mellor, Techworld (published November 24, 2006; accessed November 29, 2006)
"Can you get 256GB on an A4 sheet? No way!" By Chris Mellor, Techworld (published November 24, 2006; accessed November 29, 2006)