jack
The Legendary Troll King
Every Xerox copier uses Docucolor, btw..as do almost all the other brands.
The DocuColor series prints a rectangular grid of 15 by 8 miniscule yellow dots on every color page. The same grid is printed repeatedly over the entire page, but the repetitions of the grid are offset slightly from one another so that each grid is separated from the others. The grid is printed parallel to the edges of the page, and the offset of the grid from the edges of the page seems to vary. These dots encode up to 14 7-bit bytes of tracking information, plus row and column parity for error correction. Typically, about four of these bytes were unused (depending on printer model), giving 10 bytes of useful data. Below, we explain how to extract serial number, date, and time from these dots.
DocuColor output seen under white light
DocuColor output seen under blue light - yellow is seen as black when viewed under blue light
DocuColor printer forensic codes revealed
The DocuColor series prints a rectangular grid of 15 by 8 miniscule yellow dots on every color page. The same grid is printed repeatedly over the entire page, but the repetitions of the grid are offset slightly from one another so that each grid is separated from the others. The grid is printed parallel to the edges of the page, and the offset of the grid from the edges of the page seems to vary. These dots encode up to 14 7-bit bytes of tracking information, plus row and column parity for error correction. Typically, about four of these bytes were unused (depending on printer model), giving 10 bytes of useful data. Below, we explain how to extract serial number, date, and time from these dots.
DocuColor output seen under white light
DocuColor output seen under blue light - yellow is seen as black when viewed under blue light
DocuColor printer forensic codes revealed
