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Figure 3-8.Electronic imaging workstation centered around an AT computer

Photography (Advanced) - Advanced manual for photography and other graphic techniques
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make color corrections before the image is scanned into a digital file. By making these adjustments before scanning an image, you can save time and file size. Scanners are produced by a number of manufacturers. Scanners used in Navy imaging facilities are produced by Nikon and Kodak (fig. 3-7). Once an image is converted to digital format, the data is passed from the scanner to the computer through an interface. Because of the enormous amount of data involved in electronic imaging, information is passed through a SCSI. A SCSI is a special kind of parallel interface that allows for faster data transmission. The SCSI interface permits  a  number  of  peripheral  devices  to  be  connected to  the  computer  through  a  single  SCSI  port.  This  is accomplished by chaining the devices together with a SCSI cable. The last device in the chain must have a special adapter, known as a terminator. Some devices have built-in terminators. Each device in the SCSI chain is identified by a unique identification number. When the scanner is connected, you  must verify that none of the peripherals have  the  same  identification  number.  These identification numbers may be changed by using either dipswitch  settings  or  software. The scanner uses two programs to operate. One program is a paint program to manipulate the image once it is in the computer. The second program is a driver that acts as a translator between the scanner and the paint   program.  Once  the  image  is  digitized, Figure 3-7.—Kodak 7720 thermal-dye transfer printer. limitless modifications and enhancements can be made to  the  image. Because a scanner scans at such high resolution, the end file is quite large. Thus a considerable amount of storage space is required. It is common for a 24-bit color image to require 20 to 25 megabytes of storage. COMPUTER PLATFORM AND SOFTWARE The  entire  electronic  workstation  is  designed around a computer (fig. 3-8). There are three major computer  platforms  in  use  for  digital  photography—the Apple Macintosh, PCs (IBM or compatibles), and Unix-based machines. The most popular computer for digital imaging is the Apple Macintosh. However, PCs and  IBM  compatibles  are  also  used  for  digital  imaging. They  are  becoming  more  popular  in  the  digital-imaging marketplace. Unix-based workstations are used for science-oriented   operations   and   high-volume publishing of books and technical manuals. Therefore, Unix-based  machines  are  not  commonly  found  in  Navy imaging  facilities. Regardless of whether you are using an IBM compatible or a Macintosh platform for electronic imaging,  the  applications  are  basically  the  same. Specific computer systems are not covered in this training  manual. Only the principles that apply to electronic imaging are discussed. Computer  Configurations As a guideline, the computer must have a minimum of 8Mb of RAM.  For work efficiency, you need at least 32Mb of RAM. Storage may also become a problem because of the large-size file of color digital images. A high-resolution  scanned  image  can  require  250 megabytes or more of memory.  A hard drive in excess of 600Mb is not uncommon for an electronic-imaging workstation. The  computer  system  must  also  have  sufficient expansion  slots  to  install  interface  cards  for  add-on peripherals, such as scanners, film recorders, and printers. A number of interface cards are available for both Macintosh and PCs that convert analog images to digital  format. Software Like computer platforms, a vast number of software packages  are  available  for  scanning  and  modifying images.  Computer  software  (programs)  makes  it possible for you to communicate with the hardware. 3-11







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