| Summary
A key component in all imaging devices is the image sensor.
Most often, the sensor is a charge-coupled device (CCD), which
converts light into electrical signals. A CCD consists of an array
of individual semiconductors. The dimensions of the array (e.g.
1504x2008) determines the image resolution. A newer type of sensor,
the CMOS sensor, produces images of better quality than traditional
CCDs. A digital camera most often stores images in a solid-state
storage device (such as CompactFlash, SmartMedia and Memory Stick)
until they are transferred to a computer. Intraoral cameras, on
the other hand, are directly connected to a computer, which displays
acquired images immediately. Image storage media differ in their
capacity and speed. Depending on image quality, most digital cameras
can store between 10 and 200 images before the storage medium
is full. Options for outputting and transmitting images include
photo and inkjet printers, laser printers, slides, commercial
photo services, and e-mail and electronic attachments. |
Objectives
After studying this chapter, you should be able to:
- explain how an image sensor acquires an image
- relate sensor attributes to image quality, such as color depth
and resolution
- identify different ways of transmitting images from an acquisition
device to a computer
- list different image storage media and compare their attributes
- describe the process of image acquisition and transmission
in digital cameras, intraoral cameras and digital radiology
sensors
- contrast different image output mechanisms and identify their
primary applications
- compare output quality of monitors, inkjet and photo printers
and laser printers
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Benefits
Understanding the material in this chapter will increase
your ability to:
- understand technical specifications for image acquisition
devices
- choose an optimal sensor type for your needs
- understand the benefits and drawbacks of different methods
of transferring an image from an acquisition device to a computer
- differentiate between different image storage media and compare
their advantages and disadvantages
- choose one or more image output methods suitable to your
needs
- understand how to transmit images securely over the Internet
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Key Concepts
- image acquisition
- image sensor (CCD)
- mosaic-based and CMOS sensors
- sensor array
- interpolation
- optical and digital zoom
- image storage media (such as CompactFlash, SmartMedia and
Memory Stick)
- downloading
- inkjet and photo printers
- laser printers
- commercial photo and slide printing services
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