An Overview Of Digital ImagingThe capturing of images is a subject that has fascinated us for quite a long time. The discipline of imaging has come a long way from the first camera and techniques of image development. Digital imaging, the discipline of acquiring and manipulating images in a digital format has really taken off after the 1990s because of the decreasing costs of advanced hardware and the availability of powerful software capable of manipulating digital images. In a very narrow sense digital imaging is the capture of an image through a medium such as a digital camera; also known as digital photography. However to take the definition a step further, digital imaging also includes the acquisition of an image by the scanning of an existing document or an analog photograph using a scanner. A digital image is made up of a map of picture elements also called pixels. A pixel is the smallest unit of any digital image. Imagine a picture made up of almost countless dots not readily visible to the human eye. The greater the number of pixels in a digital image, the greater is the clarity or resolution of the picture. Each pixel in turn can be of a specific color or tone. Thus, the collection of dots or pixels forms a digital image. The resolution of a digital image is measured in megapixels or one million pixels. It is increasingly becoming the norm for digital cameras and cameras on cell phones to have a megapixel rating of around 4 to 5 megapixels. A 4-megapixel resolution is around 4 million pixels: definitely a large number of pixels to define a single digital image. Because of this format of a digital image, it is now possible like never before for the average computer user to manipulate images using a moderately powerful hardware platform and digital imaging software. The user can sharpen colors, enhance light effects, reduce the so-called noise in digital images, and create sophisticated slide shows with annotations and music, to mention just a few capabilities. On the one hand, the digital format has resulted in a great amount of flexibility, power and freedom to play around with images, whereas on the other hand a number of issues have arisen. Determining the authenticity and integrity of a digital image is an area of increasing concern for insurance companies, forensic departments of police and law enforcement agencies, commercial institutions and hospitals. A number of techniques and algorithms are being developed to determine the authenticity and integrity of digital images. In the meanwhile, camera and cellphone manufacturers are in the race to provide an increasing number of power packed features that will provide even the novice camera user with a lot of power and resolution to capture excellent digital images. Digital imaging should not be considered as synonymous with digital photography. It has a much wider scope that includes the generation of images using technologies such as computer aided tomography (CAT) scans, magnetic resonance imaging (MRI) scans and imaging radar. In whatever way we look at it, this discipline has made life richer for all of us. Digital imaging has provided us with capabilities that were virtually unthinkable just about two to 3 decades ago. |