The many dimensions of imaging
Imaging-that is, the acquisition, processing, and presentation of images-spans an entire spectrum of technologies, starting with the detector or imager and ending up with .
Imaging-that is, the acquisition, processing, and presentation of images-spans an entire spectrum of technologies, starting with the detector or imager and ending up with . . . well that depends, of course, on the particular application and how the images will be used. Much recent development effort in the imaging arena has focused on security and trying to teach computers and software to “read” and respond to images that you and I also understand-facial-recognition systems, for instance, look for faces in a crowd, license-plate imagers “read” (and record) the plate numbers of passing vehicles, while industrial vision systems watch manufacturing lines looking for anomalies in the finished product.
But there have also been developments in a different imaging technology. Instead of teaching machines to do what humans can do, specialized systems can interpret machine-readable coding that’s unintelligible to humans-and they can do it very efficiently. The “images” are developed with a specific task in mind, and because the only reader is a machine, these images-which started out in 1974 as simple linear barcodes and have subsequently evolved into two-dimensional hieroglyphics-can be very small. And in their most recent embodiment they can also be quite secure (see cover and p. 69).
Yet another aspect of imaging involves looking into, around, or through something opaque-all tasks impossible for an unaided human eye. Whether the application is security, quality assurance, or testing, “seeing inside” has become critical to our everyday lives. X-ray systems at airports and in hospitals are now ubiquitous, but equally sophisticated imagers are evolving based on terahertz technology that can nondestructively image inside microprocessors or the wings of a spacecraft, as well as show the distribution of active ingredient inside a pharmaceutical pill (see p. 109). These terahertz systems are currently very expensive, however-a frequent hurdle for new technologies, including another evolving imaging technique that’s expected to open (or see through?) new doors: real-time imaging ladar in three dimensions (see p. 89).
Stephen G. Anderson
Associate Publisher/Editor in Chief