Abstract
Over the last decade, digital imaging technology has made major strides within the commercial market. Digital imaging has come a long way with major improvements in computer performance and capacity. There are several digit formats including TIFF (tag image file format), JPEG (joint photographic experts group), and BMP (bitmap). Diagnostic imaging modalities are moving very quickly into the digital domain. This presentation is intended to provide insight into the state-of-the-art of digital imaging. This presentation will also address requirements for digital image storage including image compression and manipulation.
Digital imaging has moved out of the hands of high-end computer workstations and into the world of commercially available off-the-shelf personal computers (PC). Image handling does require noted RAM requirements and large enough hard drive space to move and store images with little concern to the user. Minimum specifications are now based on such issues as how fast do you need to bring the images up for display, display resolution, how large are these images (digital size), and the size of the total database.
Digital cameras, scanning devices, and video capture cards that produce and or convert optical to digital images are now on the commercial market and have well defined format specifications. This discussion will not go into great detail on these systems other than to say that digital image capture and conversion (optical to digital) is becoming a well-established commercial technology. One on-going issue regarding digital image capture is resolution. How much resolution is good enough? In the case of radiographs, standards are currently being set to establish which technology should be used to provide the quality needed to resolve the points of interest. This is a major issue in establishing the system specifications and requirements for diagnostic digital imaging modalities.
On the market today, there are many commercially available image processing packages. These software systems allow you to digitally enhance images. These functions include magnification (pan and zoom), filtering (edge enhancement), contrast, brightness, hue, as well as annotation, overlay capabilities, and database development. Some systems will also allow image fusion or being able to overlay various imaging modalities on to one another.
Other systems can create three-dimensional modeling. These systems are intended to enhance the image and to bring out features that might not otherwise be identified. For the most part these systems will be compatible with PC based systems (Windows based).
Digital image storage is important to consider when defining your computer system requirements. There is a huge difference when working with 320×240 images vs. 4×4 kbyte images. Space can be used up very quickly. In most cases, images of large size can and should be compressed (JPEG) for storage and segmented for handling ease. When archiving images, an external device could be used to store images offline (Zip Disks). In the case of networked systems, a computer could be designated as a repository for your images. With the interest in global networking (e-mail), a consideration should be given to image management and handling.
Digital imaging is a rapidly expanding area of technology which offers the veterinarian tremendous diagnostic and research opportunities. The application of diagnostic imaging and medical record-keeping databases will merge over the next couple of years. Digital images will provide the information that once was filed away with hard copy film or stored in disjointed files. Over the next few years, universities and zoological facilities will be using systems which encompass digital imaging to manage and maintain the health and well-being of their animal population. As the old adage goes, “an image can speak a thousand words,” a digital image can speak megabytes of information.