Image Acquisition Devices

Image Acquisition Devices

We humans depend more on our eyes to understand and process information. Differences exist between how humans perceive an image for its quality and how the image is processed on a computer system. As we have seen earlier, the first step in digital image production is acquisition. Digital images are acquired in a number of ways and stored as data. The most common image acquisition methods are mentioned below:
Scanning: A scanner is a device used to obtain a digital copy of an image. The image can be available in paper, photograph, a negative film, slides, etc. Scanners are easy to use and they can be quickly installed to work with a computer. The scanned image is stored on the computer's disk as data. One type of scanner is called the flatbed scanner which works similar to a photocopier, the lid is raised each time to change the picture or photograph inside for scanning. The other type of scanner that is available is called photo-print, slide and negative scanner. This type of scanner can take a stack of images (photographs) and scan them one after the other automatically, thus eliminating the need for raising the lid each time.

Digital Cameras: Digital cameras are image capturing devices and probably the easiest way to digitize images. The acquisition method is simple and fast. These cameras are available in a wide range of performance characteristics with the popularly available brands. The method of image capture is similar to a normal film based camera, but the captured image is stored on a memory chip as data in one standard format, normally JPG. The acquired image can be transferred into a computer easily. Digital cameras have variable settings for image quality (resolution). The performance and quality of images and other functionalities available in the camera are varied and based on price.

Video Cameras: Video cameras are the most common and affordable way of acquiring images for computer processing. This device uses the appropriate optics and electronics to capture moving images and for storing them on a computer.

Other devices such as telescopes, microscopes, CCD (charge couple device) cameras, etc. are also used for image acquiring and storing them digitally.