With the evolution of electronic imaging, the technology involved today in the creation, manipulation, and distribution of images allows photographers to perform functions that they only dreamed of a decade ago. Procedures that once took hours or even days in the conventional darkroom can now be accomplished within minutes under normal room lights and without getting your hands wet. With the electronic medium, images may be created, modified, and enhanced, The end product is limited only by your imagination. Several distinct advantages of electronic imaging as compared to conventional photography are in use today. These advantages are as follows:

It saves the time required in conventional development and printing.

It saves money by eliminating direct and indirect costs related to developing and printing photographs.

It is environmentally friendly. It can be viewed immediately. Images can be transmitted instantly and rapidly using standard telephone lines.

Electronic imaging used in the Navy today ranges from capturing and processing an image through an electronic medium to conventional silver-halide technology and electronic processing by way of a hybrid system. Because of the dynamic advances in this growing field, this chapter is intended only as a brief overview of the basic principles and applications of electronic imaging. To be prepared for this fascinating technology, you must become familiar with computer systems, electronic imaging, and the equipment used to create digital images.

BASIC COMPUTER FUNDAMENTALS

Computers are often compared to people since both have the ability to accept information, work with it, store it, retrieve it, and provide information output. The primary difference is that people have the ability to perform all of these actions independently without outside assistance. People also think and control their own actions. The computer, however, requires a program (a predefined set of instructions) to accomplish an assigned task. People receive information in several different forms, such as eyes, ears, nose, mouth, and even sensory nerves. Our brain receives and accepts this information, works with it in some manner, and then stores it somewhere in the back of our mind (memory) for future use. If information at the time requires immediate attention, our mind directs us to respond with words or actions. Likewise, the brain of a computer is the central processing unit (CPU). The CPU is designed to do basically the same thing; that is, it receives information (input data), works with this information (processes data), and transmits this information (output data) to some form of output media.

Computers are incapable of independent thought or action; they can do nothing more than perform the instructions given to them. Computers simply follow a set of instructions stored internally (called a program) and process the input data. Then when all the steps are followed properly, the computer provides an end result that you can work with.

The computers used in electronic imaging are general-purpose digital computers. These general-purpose computers are capable of performing operations, such as word processing, graphic applications, and spread sheet because they can store a wide variety of programs in internal storage.

COMPONENTS OF A DIGITAL COMPUTER

Components, or tools, of a computer system are grouped into two categories: HARDWARE and SOFTWARE. Hardware consists of the machines that comprise a computer system, such as all the mechanical, electrical, electronic, and magnetic devices within the computer itself and all related PERIPHERAL devices. The peripheral devices consist of items, such as a keyboard, magnetic tape unit, mouse, scanner, printer, and so on. The software items are programs and operating aids written so the computer can process data. The manufacturer supplies much of the initial software for a particular computer. This software is known as SYSTEMS SOFTWARE. Systems software is designed for broad general use. Examples of systems software are DOS (disk operating system) for IBM compatible computers and System 7 for Apple computers. Software designed to meet a specific requirement or purpose is called APPLICATION SOFTWARE. Examples of application software are WordPerfect, Lotus 1-2-3, and Adobe Photoshop.