Originating in the Holy Roman Empire, the printing press was perfected in 1440, and quickly established itself as one of the most influential inventions of the millennium1, drastically reducing the cost and time involved with printing books and documents. The printing press helped advance the spread of mass communications, and by the Renaissance, millions of books were in wide publication1
Printed works need to be digitized for preservation and propagation. Bookscanner SA is the manufacturer of Bookscanner© scanning equipment, which is suitable for automatically digitizing printed material up to A1 page size. The scanning equipment makes use of state-of-the-art methods to precisely and reliably reproduce printed pages. Their primary clients are private and national libraries, with typical collections numbering about 5,000 volumes; these clients each face challenges with the time-consuming and labor-intensive process of digitizing these works. George Pistikos—an electrical and computer engineer with more than 20 years of experience developing information and computer systems—founded Bookscanner SA with the aim to “relieve humanity from repetitive and tedious jobs using cutting-edge robotics techniques.”
One for the books
For their installation in Greece, Bookscanner SA sought to enhance their services by updating their technology. Their camera of choice was the Teledyne e2v ELiiXA+, a 16K CoaXpress® line-scan camera with resolutions up to 600 dpi. In researching compatible software and hardware components, Bookscanner SA discovered that Matrox Imaging offers a compatible, plug-and-play solution built on the robust Matrox Imaging Library (MIL) platform. MIL-Lite, a subset of MIL, includes a range of programming functions for image capture, display, and annotation; the application programming interface (API) is simple to use and supports the most common programming languages, including C++, C#, and Visual Basic®. Paired with the Matrox Radient eV-CXP frame grabber, this solution formed the spine of Bookscanner’s machine vision infrastructure.
A real page-turner
The design of the Bookscanner system comprises a metal enclosure with a glass surface—this moves along the horizontal axis and has pistons for the page's elevation, plus sensors which monitor the proper operation of the process. A metal rod prevents the closing of the book as it moves horizontally along the glass surface; the arm-mounted line-scan camera follows the book’s trajectory during the scan. Below this glass surface, two metal sheets move via a vertically moving pulley running the length of the glass surface. Servo motors (Fujitsu Alpha 5 Smart) power the Bookscanner equipment, allowing for gentle handling of each physical book to avoid any wear-and-tear, all while achieving high operating speeds of 1 m/s.
Their challenge was to synchronize the movement of the Servo motor in tandem with the image acquisition frequency rate; this synchronization was necessary to avoid any distortion of the final image. A team of computer, mechanical, and electrical engineers—namely Pistikos, along with Dr. Antonios Gasteratos, Petros Teneketzis, and Antonios Arvanitidis—combined expertise in robotics and machine vision systems to design the Bookscanner vision system. Development took about four months; the vision system was designed to be largely autonomous in operation. The operator must select the desired dpi for the output resolution level, and the scanning speed according to the fragility of the book.
“The I/O capabilities of the Matrox Radient frame grabber was absolutely necessary to our project,” said Arvanitidis. “Synchronizing the movement of the servo motor and the image acquisition frequency rate was the biggest challenge of this system. We reached out to the Matrox Imaging technical support team via email, receiving quick and accurate responses to our support needs. Matrox offers a friendly framework for integrating low-level servo encoder output signals with the input signals of the ELiiXA+ camera in order to trigger the image acquisition.” This functionality proved to be the turning point of this storyline.
A display of tremendous book smarts
With the system fully functional and deployed, the R&D department of Bookscanner SA is hard at work on the next release of the vision system’s software, introducing the ability to correct image distortion with neural networks. “This enhancement will help increase our customer base, allowing us to work with more fragile books without risk of stretching or damaging the paper,” Gasteratos noted.
Bookscanner SA is excited at the prospect of adding new machine vision techniques to the advanced robotics industry, with plans to expand their solution on both the hardware and software sides. Teneketzis affirmed that, “the machine vision techniques will be one of our main focus areas for the product. New capabilities—like grabbing based on image/pattern recognition—are going to be introduced, and Matrox Imaging will be a good partner in order to achieve our goals.”
Conclusion
Incorporating MIL-Lite and the Radient eV-CXP frame grabber into the Bookscanner system afforded an opportunity to connect high-level software abstraction with low-level electronics management; this facilitated operator changes and improved overall system functionality. With the addition of the Matrox Imaging products, Bookscanner SA reduced their development time by nearly six months, and protected their budget from additional expenses. Arvanitidis concluded, “We gained time, established the necessary communication, and successfully overcame this challenge of upgrading our vision system, thanks to the plug-and-play nature of the MIL-Lite software.”
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