DataGlyphs - encoding information in an image
The Palo Alto Research Center ( PARC ), a subsidiary of the famous U.S. corporation Xerox, has developed a system that combines paper documents intended for people with machine reading, which has a stunning advantage over previous encoding principles.
The system is called DataGlyphs .
Data is encoded in the form of many diagonal strokes (the creators of the technology called them glyphs), each of which corresponds to one bit. The value of the bit depends on the direction of the glyph.
If the equipment on which the document is printed has a sufficiently high resolution, the size of the glyphs will be very small - no more than hundredths of an inch. Due to this, hundreds of bytes of digital data can fit on a tiny section of the page. Subsequently, having scanned the document, this data can be extracted and decoded.
Each "DataGlyph" (that is, a new type of barcode) contains a synchronization grid - a regular repetition of the same set of glyphs, which marks the boundaries of printed information and increases the reliability of reading, due to the redundancy of coding.
Even with a coding redundancy rate of almost 30%, compared with the most common barcode standard - code39 (without duplication of information) - the new coding type provides almost twenty times greater data packing density: approximately 155 bytes per square centimeter (when printing on a printer with 600 dpi).
And even compared to the pdf417 standard - the most advanced barcode of previous systems - the difference is 1.8 times (in favor of DataGlyphs).
Using the variation in the thickness of neighboring glyphs and their color, glyphs can print a black-and-white or color image, the “glyphic” structure of which will be invisible to the eye (as we do not see dots of different diameters when printing photographs in a newspaper).
Arguing further, glyphs can be used to make a gray background on text documents that contains the document itself in digital form. This technology of double-sided printing of one and the same document (one side with “letters” is for people, the other with “glyphs” is for machines), named by the developers of GlyphSeal, they are looking forward to more of the future. After all, now you will not need any recognition programs for printed characters for scanning, say a fax.
At one of the presentations, the developers presented a prototype scanner, which is a transparent surface on which, if you place the scanner over the encoded area, encoded information is displayed.
But most importantly, the technology is Open Source. Those who wish can get comprehensive information on the project website:http://www.parc.com/research/projects/dataglyphs/