Facts on Digital Imaging

Introduction

Film has been used for several years as the basic medium in photography to produce images. It has been used by the scientists to a larger extent for the production of numerous images by use of an optical microscope. This has been the trend until about a few decades ago when improvement in technology led to the advancement in electronic cameras and computers leading to cheaper digital imaging compared to that of using films. This paper looks at digital imaging and how it has grown making it cheaper than traditional analog imaging.

Digital imaging is also known as digital image acquisition and it refers to the making of digital images from a physical vista. Digital imaging is the process that involves the conversion of an electronic image, scanned picture or document into a sequence of dots known as pixels. Pixels stand for picture elements.  The converted image is said to be digitalized and it is stored in a storage mechanism that may be a hard drive or other electronic storage mechanism like a memory stick. The creation of the pixel involves the assigning of a value of color which is known as tonal value, of black, white, grey shades or the real color. The pixels are processed by some software for them to be retrieved and seen as real images (Kenney & Chapman, 2009).

The main difference between the digital camera and the traditional analog camera is that the traditional camera captures images by use of use of a film whereas the digital camera makes use of an electronic chip called Charged Coupling Device (CCD). CCD consists of minute diodes which are very sensitive and they are known as photosite. They convert light that fall on them into electrical impulses. The strength of the electrical impulses produced depends on the brightness of light falling on the photosite. The brighter the light the stronger the electrical impulses produced (Lee, 2007).

When the photons of light have been converted into electrical charges, a mini-computer inside the digital camera reads the electrical values stored in each of the photographs. There is an analog-to-digital converter, inbuilt, that converts the electrical values into digital values which are then stored in the storage devices of the camera. Recalling the digital values by the software and displaying them on the screen reproduces the original image which the camera or digital input mechanism captured. CCD creates a digital image which is large and cannot be easily stored in the small amount of memory in the digital camera. Consequently, there is need for the image to be compressed to the size that can be accommodated in the camera memory. This is done by the minute computer in the camera (Burdick, 2009).

Two fundamental methods are used to make the compression possible. First method involves the repetitive patterns of the image. For instance, when taking a picture of a ship moving on the sea, much of the picture will be a mass of the blue color of sea water. The camera makes recognition of several parts that make up the image which contain similar digital data; it therefore records a smaller part of the sea. It thus creates a map that shows the location of the rest of the sea. The display of the picture, later on, shows the exact position of the sea as it appears in the original image when it was captured. Therefore, the difference is that the image was compressed by the mapping techniques of the camera. The second method employs a procedure known as irrelevancy. This method involves the removal of invisible digital data such as infra red light.

The history of digital imaging shows its development to have started in 1950s. It is related to the technology that led to the development of television images. The first video tape recorder (VTR) was developed by Bing Crosby laboratories in 1951 which captured images from the cameras of the television by the conversion of the information into electrical charges, digital. The information was then saved on magnetic tapes. The VTR technology was improved greatly in 1956 and it is widely used in the television industry. The television or video cameras, digital cameras make use of CCD to sense the color and intensity of light (Lee, 2007).

In 1960s, NASA changed from utilizing analog to digital signals in their space explorations so as to map the surface of the moon. The digital images were sent back to the earth for usage. Digital imaging was also utilized in the satellites used as spies by the government. The government, in its use of digital imaging, led to its growth. However, the private sector also contributed much towards its improvement. In 1972, a film-less camera was invented by Texas Instruments. In 1981, Sony introduced the first business electronic camera called Sony Mavica. It recorded images onto a minute disc, put into reading video which was connected to color printer or television screen. Since 1970s, Kodak has introduced numerous image sensors that enable the conversion of light to digital images used for various purposes such as those used by photojournalists (Farace, 1998).

Digital camera that could be used with the computer by the use of a cable was introduced in 1994 and was known as Apple QuickTake 100 camera. In 1995, Kodak DC40 camera was introduced, in late the same year Casio QV-11 which had LCD monitor was introduced. Cyber-Shot Digital Still Camera was introduced in 1996. Kodak has invested in the promotion of DC40 thus aiding in the creation of public awareness concerning the digital photography. The companies Kinko’s together with Microsoft formed collaboration with Kodak to invent digital image producing software workstations which enabled clients to create CD discs and photos. They were also enabled to incorporate digital pictures into documents. In recent years, the collaboration of IBM and Kodak led to the introduction of image exchange based on the internet. The Hewlett-Packard Company became the first one to produce inkjet printers that produce colored images from the digital camera images (Kenney, & Chapman, 2009).

There are many advantages associated with digital imaging. Digital imaging can be used to produce images on the screen in an instantaneous manner. It is therefore speedy for such functions like digitizing radiographs, images from x-rays. This speedy showing of images on the screen saves time and it can be utilized immediately. This does not happen in the case of film photography.  Digital imaging also allows for image modifications. This is very beneficial because the qualities which are undesirable in the image can be removed whereas those which are desirable can be added. This is known as post-processing and it is useful in diagnosis where a clear image can be obtained from an unclear one (Burdick, 2009).

The quality of images produced by digital cameras is highly reliable due to their consistency. It may be claimed that an image which has been processed well through film photography has good quality but it should be noted that the production is not consistent thus unreliable. There is also reduced radiation through the use of intra-oral radiography in digital imaging. This produces much lower radiation compared to the x-rays filming. This is particularly important in the medical applications. Digital imaging does not make use of chemicals. Thus there is money saving by avoiding films and chemical processing. Problems related with the handling and storage as well as the disposing off of chemicals are also avoided. Therefore, there is increased efficiency in the handling and retrieving records of patients and space is not a problem in digital imaging (Farace, 1998).

Conclusion

From the above discussion, digital imaging can be seen to have improved over the years. The factors which led to faster improvement are associated with it being cheap and efficient compared to the traditional analog film imaging. Digital imaging started in early 1950s in a simple manner. However, it can be seen that it has greatly advanced in modern times and it is being utilized for various purposes including photojournalism. It is also useful in medical sector. Its many advantages, such as speed and quality, over the traditional imaging makes it to have wide applications.

 

References

Burdick, H. E., (2009). Digital imaging: theory and applications. McGraw-Hill.

Farace, J., (1998). Digital imaging: tips, tools, and techniques for photographers. Focal Press

Kenney, A. R., & Chapman, S., (2009). Digital imaging for libraries and archives. Dept. of Preservation and Conservation, Cornell University Library.

Lee, S. D., (2007). Digital imaging: a practical handbook. Neal-Schuman Publishers in association with Library Association Pub.