Presented at the 2000 APIII Conference Return to 2000 Abstract Index
REPURPOSING INSTRUCTIONAL MATERIALS USING AUTOMATED DIGITAL CONVERSION OF ANALOG VIDEODISC IMAGE RESOURCES
University
of Alabama at Birmingham
Birmingham, Alabama
Peter G. Anderson, DVM, PhD
Peter G. Anderson, Kristopher N. Jones, Dwain E. Woode,
Kristina T.C. Panizzi
Department of Pathology, University of Alabama at Birmingham
Background: Videodiscs have been a standard technology for archiving and distributing medical images. Videodisc technology allows over 50,000 still analog images or 30 minutes of motion (or a combination, thereof) to be stored on each side of a 12-inch disc. Many ambitious medical education projects—most notably the Slice of Life project, a videodisc offering of over 44,000 images from a breadth of medical disciplines—have thrived using the technology. However, videodisc images cannot be used in digital presentations or distributed over the Web without first digitizing the images from their analog videodisc source. This digital capture process can be tedious and produces images of marginal quality. Without digital conversion, however, many educational resources archived on videodisc are unavailable for use. The purpose of this project was to create an automated process for batch converting analog videodisc images to digital versions.
Design: A videodisc player with high-quality digital comb filters, S-video output, and an RS-232 serial communications port for computer control was chosen as the source device and connected to a digital capture card on a personal computer running Windows 2000. A legacy program for controlling the videodisc player via the RS-232 port was obtained from the manufacturer and the capture process was automated using a batch program and a command-line keystroke automater.
Results: By automating the capture process, 5 images per minute could be captured on a continuous basis—i.e., 7200 images a day. Using this technique, we were able to capture in 3 days’ time approximately 18,000 public-access images from the Slice of Life project and another 5,000 images from the National Library of Medicine’s Basic Medical Pathology laserdisc series. Through interpolation by the capture software, the images were captured at 1600 x 1200 pixels, resulting in a 5.5 Mb TIFF output file per image.
Conclusion: This automated process for converting analog videodisc images to digital image files facilitates the repurposing of thousands of archived videodisc images for continued use and development of digital teaching materials that may be distributed on CD-ROM or via the Internet. Using this process, we have digitized images from the Slice of Life project and the National Library of Medicine’s Basic Medical Pathology series for use in our Pathology Education Instructional Resource image database.
