Automation of gross photography using a remote-controlled digital camera system

Archives of Pathology & Laboratory Medicine, Jun 2003 by Park, Rae-Woong, Eom, Joon-Hoe, Byun, Ho-Yong, Park, Peom, Et al

* Context.-Conventional gross photography requires a series of tedious and time-consuming steps, including taking, developing, labeling, sorting, filing, and tracking numerous photographs.

Objective.-To describe how to automate the gross photographic process by way of controlling a digital camera remotely.

Design.-After defining the requirements of automation regarding gross photography, a remote control board, foot switch, barcode system, and image retrieval system were devised.

Setting.-The surgical pathology laboratory of a university medical center with a commercially available megapixel digital camera.

Results.-The digital camera zoom and shutter were controlled remotely by a foot switch. A large portion of the gross photographic process, including specimen number labeling, image downloading, labeling, sorting, filing, and tracking, were automated. In addition, the elimination of several manual specimen-processing steps, along with not having to wait for the developing and mounting of conventional 35-mm film, reduced the entire time span required in conventional gross photography from 2 to 5 days, to a few minutes. It was also possible to review the gross images at the time of microscopic sign-out.

Conclusions.-The automation of gross photography using a remote-controlled digital camera changes the conventional gross workflow markedly. We found use of a remote-controlled gross photography system to be practical, convenient, and efficient.

Traditionally, gross photographs are taken using a film camera with 35-mm positive film. However, it is labor-intensive and time-consuming to take photographs and to label, sort, file, and track them in order to maintain useful photographs for daily pathology practice and academic use. Recently, megapixel digital cameras have become widely used in daily life. Digital images taken by digital cameras have very high resolution, and the quality of these images is approaching that of images taken with conventional film. Several investigators have already studied the usefulness of digital cameras compared to conventional 35-- mm cameras in routine gross photography.1-5 As Cruz and Seixas2 stated, while "a hands-free camera system would be a desirable solution," just replacing a film camera with a digital camera cannot eliminate the various laborious preprocessing and postprocessing tasks of image work.

The goals of this article are to describe the techniques of how to control a commercially available megapixel digital camera remotely, and how to adopt these images for daily pathology practice. We describe our recent experience with developing a fully automatic digital gross photography system (DGPS).

MATERIALS AND METHODS

System Requirements

To automate the gross photographic process, we defined the following goals: (1) eliminate specimen-labeling work (establish automatic recognition of specimen number); (2) establish hands-free control of the digital camera; (3) obtain live video for image framing in a photography stand; (4) automate image downloading to an image server to eliminate manual work; (5) automate image labeling, sorting, filing, and tracking; (6) set up daily batch printing of gross photographs to provide printed photographs to patients; (7) establish a gross image archival system for microscopic sign-out, conferences, education, and other academic activities; and (8) ensure that the system is easy to use.

Hardware and Software

The software system was composed of 6 main units, including the laboratory information system (LIS) connection unit, camera control unit, controller unit, image name mapping unit, image server, and barcode unit. We prepared a data-connection interface for linkage with other laboratory information systems, order communication systems, and/or picture archiving and communication systems. The program was implemented in Microsoft Visual Basic 6.0 (Microsoft, Redmond, Wash). Microsoft Access 2000 (Microsoft) software was used, running under the Windows 2000 (Microsoft) operating system. For hardware, we used general-purpose products that are easily available in the consumer market. These hardware items consisted of a typical personal computer (128 MB memory), liquid crystal display monitor, digital camera (Coolpix 995, Nikon Co, Tokyo, Japan), video grabber board, foot switch, control board, barcode reader, barcode printer, and photography stand (Figure 1). However, it was necessary to devise a specialized control board and cable to control the digital camera remotely (Figure 2).

Selection of a Suitable Digital Camera

Images with resolutions greater than 150 dots per inch (dpi) look natural to the human eye, yet most publishing companies use an image resolution of 300 dpi in their publications. Therefore, the recommended number of image pixels for a 5 X 7-inch print might be 1500 X 2100 pixels (about 3.15 megapixels). Barker et al6 suggested that a resolution of 1450 x 2048 pixels is necessary for 5 x 7-inch prints. When we assume that gross photographs taken for academic purposes should have a maximum size of 5 x 7 inches, the lower acceptable limit for resolution is about 3.0 megapixels. Therefore, any potential digital camera used in DGPS must have a resolution higher than 3.0 megapixels. About 90 such cameras are currently on the market.