Digital imaging

From Wikipedia, the free encyclopedia

Digital imaging or digital image acquisition is the creation of digital images, typically from a physical scene. The term is often assumed to imply or include the processing, compression, storage, printing, and display of such images. The most usual method is by digital photography with a digital camera but other methods are also employed.

History

Digital imaging was developed in the 1960s and 1970s, largely to avoid the operational weaknesses of film cameras, for scientific and military missions including the KH-11 program. As digital technology became cheaper in later decades, it replaced the old film methods for many purposes.

The first digital image was produced in 1920, by the Bartlane cable picture transmission system. British inventors, Harry G. Bartholomew and Maynard D. McFarlane, developed this method. The process consisted of “a series of negatives on zinc plates that were exposed for varying lengths of time, thus producing varying densities,”.[1] The Bartlane cable picture transmission system generated at both its transmitter and its receiver end a punched data card or tape that was recreated as an image.[2]

In 1957, Russell A. Kirsch produced a device that generated digital data that could be stored in a computer; this used a drum scanner and photomultiplier tube.[1]

In the early 1960s, while developing compact, lightweight, portable equipment for the onboard nondestructive testing of naval aircraft, Frederick G. Weighart[3] and James F. McNulty[4] at Automation Industries, Inc., then, in El Segundo, California co-invented the first apparatus to generate a digital image in real-time, which image was a fluoroscopic digital radiograph. Square wave signals were detected by the pixels of a cathode ray tube to create the image.

These different scanning ideas were the basis of the first designs of digital camera. Early cameras took a long time to capture an image and were poorly suited for consumer purposes.[1] It wasn’t until the development of the CCD (charge-coupled device) that the digital camera really took off. The CCD became part of the imaging systems used in telescopes, the first black and white digital cameras and camcorders in the 1980s.[1] Color was eventually added to the CCD and is a usual feature of cameras today.

The changing environment

Great strides have been made in the field of digital imaging. Negatives and exposure are foreign concepts to many, and the first digital image in 1920 led eventually to cheaper equipment, increasingly powerful yet simple software, and the growth of the Internet.[5]

The constant advancement and production of physical equipment and hardware related to digital imaging has effected the environment surrounding the field. From cameras and webcams to printers and scanners, the hardware is becoming sleeker, thinner, faster, and cheaper. As the cost of equipment decreases, the market for new enthusiasts widens, allowing more consumers to experience the thrill of creating their own images.

Everyday personal laptops, family desktops, and company computers are able to handle photographic software. Our computers are more powerful machines with increasing capacities for running programs of any kind—especially digital imaging software. And that software is quickly becoming both smarter and simpler. Although functions on today’s programs reach the level of precise editing and even rendering 3-D images, user interfaces are designed to be friendly to advanced users as well as first-time fans.

The Internet allows editing, viewing, and sharing digital photos and graphics A quick browse around the web can easily turn up graphic artwork from budding artists, news photos from around the world, corporate images of new products and services, and much more. The Internet has clearly proven itself a catalyst in fostering the growth of digital imaging.

Online photo sharing of images changes the way we understand photography and photographers. Online sites such as Flikr, Shutterfly, and Instagram give billions the capability to share their photography, whether they are amateurs or professionals. Photography has gone from being a luxury medium of communication and sharing to more of a fleeting moment in time. Subjects have also changed. Pictures used to be primarily taken of people and family. Now, we take them of anything. We can document our day and share it with everyone with the touch of our fingers. [6]

Field advancements

Digital imaging has demonstrated its worth in a variety of fields from education to medicine. As digital projectors, screens, and graphics find their way to the classroom, teachers and students alike are benefitting from the increased convenience and communication they provide, although their theft can be a common problem in schools.[7] In addition acquiring a basic digital imaging education is becoming increasingly important for young professionals. Reed, a design production expert from Western Washington University, stressed the importance of using “digital concepts to familiarize students with the exciting and rewarding technologies found in one of the major industries of the 21st century”.[5]

The field of medical imaging, a branch of digital imaging that seeks to assist in the diagnosis and treatment of diseases, is growing at a rapid rate. A recent study by the American Academy of Pediatrics suggests that proper imaging of children who may have appendicitis may reduce the amount of appendectomies needed. Further advancements include amazingly detailed and accurate imaging of the brain, lungs, tendons, and other parts of the body—images that can be used by health professionals to better serve patients.[8]

There is a program called Digital Imaging in Communications and Medicine (DICOM) that is changing the medical world as we know it. DICOM is not only a system for taking high quality images of the aforementioned internal organs, but also is helpful in processing those images. It is a universal system that incorporates image processing, sharing, and analyzing for the convenience of patient comfort and understanding. This service is all encompassing and is beginning a necessity.[9]

Theoretical application

Although theories are quickly becoming realities in today’s technological society, the range of possibilities for digital imaging is wide open. One major application that is still in the works is that of child safety and protection. How can we use digital imaging to better protect our kids? Kodak’s program, Kids Identification Digital Software (KIDS) may answer that question. The beginnings include a digital imaging kit to be used to compile student identification photos, which would be useful during medical emergencies and crimes. More powerful and advanced versions of applications such as these are still developing, with increased features constantly being tested and added.[10]

But parents and schools aren’t the only ones who see benefits in databases such as these. Criminal investigation offices, such as police precincts, state crime labs, and even federal bureaus have realized the importance of digital imaging in analyzing fingerprints and evidence, making arrests, and maintaining safe communities. As the field of digital imaging evolves, so does our ability to protect the public.[11]

Digital imaging can be closely related to the social presence theory especially when referring to the social media aspect of images captured by our phones. There are many different definitions of the social presence theory but two that clearly define what it is would be "the degree to which people are perceived as real" (Gunawardena, 1995), and "the ability to project themselves socially and emotionally as real people" (Garrison, 2000). Digital imaging allows one to manifest their social life through images in order to give the sense of their presence to the virtual world. The presence of those images acts as an extension of oneself to others, giving a digital representation of what it is they are doing and who they are with. Digital imaging in the sense of cameras on phones helps facilitate this effect of presence with friends on social media. Alexander (2012) states, "presence and representation is deeply engraved into our reflections on images...this is, of course, an altered presence...nobody confuses an image with the representation reality. But we allow ourselves to be taken in by that representation, and only that 'representation' is able to show the liveliness of the absentee in a believable way." Therefore, digital imaging allows ourselves to be represented in a way so as to reflect our social presence. [12]

Methods

A digital photograph may be created directly from a physical scene by a camera or similar device. Alternatively, a digital image may be obtained from another image in an analog medium, such as photographs, photographic film, or printed paper, by an image scanner or similar device. Many technical images—such as those acquired with tomographic equipment, side-scan sonar, or radio telescopes—are actually obtained by complex processing of non-image data. Weather radar maps as seen on television news are a commonplace example. The digitalization of analog real-world data is known as digitizing, and involves sampling (discretization) and quantization.

Finally, a digital image can also be computed from a geometric model or mathematical formula. In this case the name image synthesis is more appropriate, and it is more often known as rendering.

Digital image authentication is an issue[13] for the providers and producers of digital images such as health care organizations, law enforcement agencies and insurance companies. There are methods emerging in forensic photography to analyze a digital image and determine if it has been altered.

Previously digital imaging depended on chemical and mechanical processes, now all these processes have converted to electronic. A few things need to take place for digital imaging to occur, the light energy converts to electrical energy- think of a grid with millions of little solar cells. Each condition generates a specific electrical charge. Charges for each of these "solar cells" are transported and communicated to the firmware to be interpreted. The firmware is what understands and translates the color and other light qualities. Pixels are what is noticed next, with varying intensities they create and cause different colors, creating a picture or image. Finally the firmware records the information for future and further reproduction.

Advantages

There are several benefits of digital imaging. First, the process enables easy access of photographs and word documents. Google is at the forefront of this ‘revolution,’ with its mission to digitize the world’s books. Such digitization will make the books searchable, thus making participating libraries, such as Stanford University and the University of California Berkley, accessible worldwide.[14] Digital imaging also benefits the medical world because it “allows the electronic transmission of images to third-party providers, referring dentists, consultants, and insurance carriers via a modem”.[14] The process “is also environmentally friendly since it does not require chemical processing”.[14] Digital imaging is also frequently used to help document and record historical, scientific and personal life events.[15]

Benefits also exist regarding photographs. Digital imaging will reduce the need for physical contact with original images.[16] Furthermore, digital imaging creates the possibility of reconstructing the visual contents of partially damaged photographs, thus eliminating the potential that the original would be modified or destroyed.[16] In addition, photographers will be “freed from being ‘chained’ to the darkroom,” will have more time to shoot and will be able to cover assignments more effectively.[17] Digital imaging ‘means’ that “photographers no longer have to rush their film to the office, so they can stay on location longer while still meeting deadlines”.[18]

Another advantage to digital photography is that it has been expanded to camera phones. We are able to take cameras with us wherever as well as send photos instantly to others. It is easy for people to us as well as help in the process of self-identification for the younger generation[19]

Drawbacks

Critics of digital imaging cite several negative consequences. An increased “flexibility in getting better quality images to the readers” will tempt editors, photographers and journalists to manipulate photographs.[17] In addition, “staff photographers will no longer be photojournalistists, but camera operators…as editors have the power to decide what they want ‘shot’”.[17] Legal constraints, including copyright, pose another concern: will copyright infringement occur as documents are digitized and copying becomes easier?

See also

References

  1. ↑ 1.0 1.1 1.2 1.3 Trussell H &Vrhel M (2008). "Introduction". Fundamental of Digital Imaging: 1–6. 
  2. ↑ ”The Birth of Digital Phototelegraphy”, the papers of Technical Meeting in History of Electrical Engineering IEEE, Vol. HEE-03, No. 9-12, pp 7-12 (2003)
  3. ↑ U.S. Patent 3,277,302, titled “X-Ray Apparatus Having Means for Supplying An Alternating Square Wave Voltage to the X-Ray Tube”, granted to Weighart on October 4, 1964, showing its patent application date as May 10, 1963 and at lines 1-6 of its column 4, also, noting James F. McNulty’s earlier filed co-pending application for an essential component of invention
  4. ↑ U.S. Patent 3,289,000, titled “Means for Separately Controlling the Filament Current and Voltage on a X-Ray Tube”, granted to McNulty on November 29, 1966 and showing its patent application date as March 5, 1963
  5. ↑ 5.0 5.1 Reed, Mike (2002). "Graphic arts, digital imaging and technology education". T H E Journal 21 (5): 69+. Retrieved 28 June 2012. (subscription required)
  6. ↑ Murray, Susan (August 2008). "Digital Images, Photo-Sharing, and Our Shifting Notions of Everyday Aesthetics". Journal of Visual Culture 7 (2): 147–163. doi:10.1177/1470412908091935.  (subscription required)
  7. ↑ Richardson, Ronny (2003). "Digital imaging: The wave of the future". T H E Journal 31 (3). Retrieved 28 June 2012. 
  8. ↑ Bachur, R. G.; Hennelly, K.; Callahan, M. J.; Chen, C.; Monuteaux, M. C. "Diagnostic Imaging and Negative Appendectomy Rates in Children: Effects of Age and Gender". Pediatrics 129 (5): 877–884. doi:10.1542/peds.2011-3375. 
  9. ↑ Planykh, Oleg, S. (2009). Digital Imaging in Communications in Medicine: A Practical Introduction and Survival Guide. Boston, Mass.: Springer. p. 3-5. ISBN 9783642108495. 
  10. ↑ Willis, William (1997). "Digital imaging is innovative, useful, and now within educators’ reach". T H E Journal 25 (2): 24+. Retrieved 28 June 2012. 
  11. ↑ Cherry, Michael; Edward Imwinkelried (2006). "A cautionary note about fingerprint analysis and reliance on digital technology". Judicature 89 (6): 334+. Retrieved 28 June 2012. 
  12. ↑ Alexander, J. C. (2012). Iconic Power: Materiality and meaning in social life. New York: Palgrave Macmillan. 
  13. ↑ Digital image authentication for evidence.
  14. ↑ 14.0 14.1 14.2 Michels, S. (December 30, 2009). "Google’s Goal: Digitize Every Book Ever Printed". PBS Newshour. Retrieved 2 October 2012. 
  15. ↑ Gustavson, T. (2009). Camera: A history of photography from daguerreotype to digital. New York: Sterling Innovation.
  16. ↑ 16.0 16.1 Frey S (1999). "Digital Imaging as a Tool for Preservation". IADA preprints: 191–4. 
  17. ↑ 17.0 17.1 17.2 Parker D (1988). "Ethical Implications of Electronic Still Cameras and Computer Digital Imaging in the Print Media". Journal of the Mass Media 3 (2): 47–59. 
  18. ↑ Fahmy S, Smith CZ (2003). "Photographers Note Digital's Advantages, Disadvantages". Newspaper Research Journal 24 (2): 82–96. 
  19. ↑ Gai, B. (2009). "A World Through the Camera Phone Lens: A Case Study of Beijing Camera Phone Use". Knowledge, Technology, and Policy 22 (3): 195–204. 

External links

http://electronics.howstuffworks.com/cameras-photography/digital/digital-camera.htm

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